diff --git a/lib/PowerShell/Constants.js b/lib/PowerShell/Constants.js
index e47bba72..98f75ccf 100644
--- a/lib/PowerShell/Constants.js
+++ b/lib/PowerShell/Constants.js
@@ -6,6 +6,9 @@ exports.default = Constants;
 Constants.prefix = "az_";
 Constants.moduleName = "Az.Accounts";
 Constants.versionPattern = /[0-9]\.[0-9]\.[0-9]/;
-Constants.environment = "AzureCloud";
-Constants.scopeLevel = "Subscription";
-Constants.scheme = "ServicePrincipal";
+Constants.AzureCloud = "AzureCloud";
+Constants.Subscription = "Subscription";
+Constants.ServicePrincipal = "ServicePrincipal";
+Constants.Success = "Success";
+Constants.Error = "Error";
+Constants.AzVersion = "AzVersion";
diff --git a/lib/PowerShell/ServicePrincipalLogin.js b/lib/PowerShell/ServicePrincipalLogin.js
index 9dadd9e3..59900bd4 100644
--- a/lib/PowerShell/ServicePrincipalLogin.js
+++ b/lib/PowerShell/ServicePrincipalLogin.js
@@ -34,21 +34,59 @@ class ServicePrincipalLogin {
     initialize() {
         return __awaiter(this, void 0, void 0, function* () {
             Utils_1.default.setPSModulePath();
-            const azLatestVersion = yield Utils_1.default.getLatestModule(Constants_1.default.moduleName);
+            const script = new ScriptBuilder_1.default().getLatestModuleScript(Constants_1.default.moduleName);
+            const outputJson = yield this.getLatestModule(script);
+            const azLatestVersion = outputJson.Constants.AzPSVersion;
+            if (!(Constants_1.default.Success in outputJson) || !Utils_1.default.isValidVersion(azLatestVersion)) {
+                throw new Error(`Invalid AzPSVersion: ${azLatestVersion}`);
+            }
             core.debug(`Az Module version used: ${azLatestVersion}`);
             Utils_1.default.setPSModulePath(`${Constants_1.default.prefix}${azLatestVersion}`);
         });
     }
+    getLatestModule(script) {
+        return __awaiter(this, void 0, void 0, function* () {
+            let output = "";
+            const options = {
+                listeners: {
+                    stdout: (data) => {
+                        output += data.toString();
+                    }
+                }
+            };
+            yield PowerShellToolRunner_1.default.init();
+            yield PowerShellToolRunner_1.default.executePowerShellCommand(script, options);
+            return JSON.parse(output.trim());
+        });
+    }
     login() {
         return __awaiter(this, void 0, void 0, function* () {
+            let output = "";
+            const options = {
+                listeners: {
+                    stdout: (data) => {
+                        output += data.toString();
+                    }
+                }
+            };
+            const args = {
+                servicePrincipalId: this.servicePrincipalId,
+                servicePrincipalKey: this.servicePrincipalKey,
+                subscriptionId: this.subscriptionId,
+                environment: ServicePrincipalLogin.environment,
+                scopeLevel: ServicePrincipalLogin.scopeLevel
+            };
+            const script = new ScriptBuilder_1.default().getAzPSLoginScript(ServicePrincipalLogin.scheme, this.tenantId, args);
             yield PowerShellToolRunner_1.default.init();
-            const scriptBuilder = new ScriptBuilder_1.default();
-            const script = scriptBuilder.getScript(ServicePrincipalLogin.scheme, this.tenantId, this.servicePrincipalId, this.servicePrincipalKey, this.subscriptionId, ServicePrincipalLogin.environment, ServicePrincipalLogin.scopeLevel);
-            PowerShellToolRunner_1.default.executePowerShellCommand(script);
+            yield PowerShellToolRunner_1.default.executePowerShellCommand(script, options);
+            const outputJson = JSON.parse(output.trim());
+            if (!(Constants_1.default.Success in outputJson)) {
+                throw new Error(`Azure PowerShell login failed with error: ${outputJson.Constants.Error}`);
+            }
         });
     }
 }
 exports.ServicePrincipalLogin = ServicePrincipalLogin;
-ServicePrincipalLogin.environment = Constants_1.default.environment;
-ServicePrincipalLogin.scopeLevel = Constants_1.default.scopeLevel;
-ServicePrincipalLogin.scheme = Constants_1.default.scheme;
+ServicePrincipalLogin.environment = Constants_1.default.AzureCloud;
+ServicePrincipalLogin.scopeLevel = Constants_1.default.Subscription;
+ServicePrincipalLogin.scheme = Constants_1.default.ServicePrincipal;
diff --git a/lib/PowerShell/Utilities/ScriptBuilder.js b/lib/PowerShell/Utilities/ScriptBuilder.js
index 68fd9c1e..0308a0bd 100644
--- a/lib/PowerShell/Utilities/ScriptBuilder.js
+++ b/lib/PowerShell/Utilities/ScriptBuilder.js
@@ -1,20 +1,60 @@
 "use strict";
+var __importStar = (this && this.__importStar) || function (mod) {
+    if (mod && mod.__esModule) return mod;
+    var result = {};
+    if (mod != null) for (var k in mod) if (Object.hasOwnProperty.call(mod, k)) result[k] = mod[k];
+    result["default"] = mod;
+    return result;
+};
+var __importDefault = (this && this.__importDefault) || function (mod) {
+    return (mod && mod.__esModule) ? mod : { "default": mod };
+};
 Object.defineProperty(exports, "__esModule", { value: true });
+const core = __importStar(require("@actions/core"));
+const Constants_1 = __importDefault(require("../Constants"));
 class ScriptBuilder {
     constructor() {
         this.script = "";
     }
-    getScript(scheme, tenantId, servicePrincipalId, servicePrincipalKey, subscriptionId, environment, scopeLevel) {
-        this.script += `Clear-AzContext -Scope Process; Clear-AzContext -Scope CurrentUser -Force -ErrorAction SilentlyContinue;`;
-        if (scheme === "ServicePrincipal") {
-            this.script += `Connect-AzAccount -ServicePrincipal -Tenant ${tenantId} -Credential \
-            (New-Object System.Management.Automation.PSCredential('${servicePrincipalId}',(ConvertTo-SecureString ${servicePrincipalKey} -AsPlainText -Force))) \
-                -Environment ${environment};`;
-            if (scopeLevel === "Subscription") {
-                this.script += `Set-AzContext -SubscriptionId ${subscriptionId} -TenantId ${tenantId};`;
+    getAzPSLoginScript(scheme, tenantId, args) {
+        let command = `Clear-AzContext -Scope Process;
+             Clear-AzContext -Scope CurrentUser -Force -ErrorAction SilentlyContinue;`;
+        if (scheme === Constants_1.default.ServicePrincipal) {
+            command += `Connect-AzAccount -ServicePrincipal -Tenant ${tenantId} -Credential \
+            (New-Object System.Management.Automation.PSCredential('${args.servicePrincipalId}',(ConvertTo-SecureString ${args.servicePrincipalKey} -AsPlainText -Force))) \
+                -Environment ${args.environment};`;
+            if (args.scopeLevel === Constants_1.default.Subscription) {
+                command += `Set-AzContext -SubscriptionId ${args.subscriptionId} -TenantId ${tenantId};`;
             }
         }
-        this.script += `Get-AzContext`;
+        command += `Get-AzContext`;
+        this.script += `try {
+            $$ErrorActionPreference = "Stop";
+            $$output = @{};
+            ${command}
+            $$output['${Constants_1.default.Success}'] = "true";
+        }
+        catch {
+            $$output['${Constants_1.default.Error}'] = $$_.exception.Message;
+        }
+        return ConvertTo-Json $$a`;
+        core.debug(`Azure PowerShell Login Script: ${this.script}`);
+        return this.script;
+    }
+    getLatestModuleScript(moduleName) {
+        const command = `Get-Module -Name ${moduleName} -ListAvailable | Sort-Object Version -Descending | Select-Object -First 1`;
+        this.script += `try {
+            $$ErrorActionPreference = "Stop";
+            $$output = @{};
+            $$data = ${command};
+            $$output['${Constants_1.default.AzVersion}'] = $$data.Version.ToString();
+            $$output['${Constants_1.default.Success}'] = "true";
+        }
+        catch {
+            $$output['${Constants_1.default.Error}'] = $$_.exception.Message;
+        }
+        return ConvertTo-Json $$a`;
+        core.debug(`GetLatestModuleScript: ${this.script}`);
         return this.script;
     }
 }
diff --git a/lib/PowerShell/Utilities/Utils.js b/lib/PowerShell/Utilities/Utils.js
index e32d79ae..e0d6f284 100644
--- a/lib/PowerShell/Utilities/Utils.js
+++ b/lib/PowerShell/Utilities/Utils.js
@@ -1,13 +1,4 @@
 "use strict";
-var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
-    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
-    return new (P || (P = Promise))(function (resolve, reject) {
-        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
-        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
-        step((generator = generator.apply(thisArg, _arguments || [])).next());
-    });
-};
 var __importStar = (this && this.__importStar) || function (mod) {
     if (mod && mod.__esModule) return mod;
     var result = {};
@@ -21,33 +12,7 @@ var __importDefault = (this && this.__importDefault) || function (mod) {
 Object.defineProperty(exports, "__esModule", { value: true });
 const os = __importStar(require("os"));
 const Constants_1 = __importDefault(require("../Constants"));
-const PowerShellToolRunner_1 = __importDefault(require("./PowerShellToolRunner"));
 class Utils {
-    static getLatestModule(moduleName) {
-        return __awaiter(this, void 0, void 0, function* () {
-            let output = "";
-            let error = "";
-            const options = {
-                listeners: {
-                    stdout: (data) => {
-                        output += data.toString();
-                    },
-                    stderr: (data) => {
-                        error += data.toString();
-                    }
-                }
-            };
-            yield PowerShellToolRunner_1.default.init();
-            yield PowerShellToolRunner_1.default.executePowerShellCommand(`(Get-Module -Name ${moduleName} -ListAvailable | Sort-Object Version -Descending | Select-Object -First 1).Version.ToString()`, options);
-            if (!Utils.isValidVersion(output.trim())) {
-                return "";
-            }
-            return output.trim();
-        });
-    }
-    static isValidVersion(version) {
-        return !!version.match(Constants_1.default.versionPattern);
-    }
     static setPSModulePath(azPSVersion = "") {
         let modulePath = "";
         const runner = process.env.RUNNER_OS || os.type();
@@ -64,9 +29,12 @@ class Utils {
                 // TODO: add modulepath
                 break;
             default:
-                throw new Error("Unknown os");
+                throw new Error(`Unknown os: ${runner.toLowerCase()}`);
         }
         process.env.PSModulePath = `${modulePath}${process.env.PSModulePath}`;
     }
+    static isValidVersion(version) {
+        return !!version.match(Constants_1.default.versionPattern);
+    }
 }
 exports.default = Utils;
diff --git a/lib/main.js b/lib/main.js
index 4948a2a9..ca968e8b 100644
--- a/lib/main.js
+++ b/lib/main.js
@@ -44,13 +44,15 @@ function main() {
             if (!servicePrincipalId || !servicePrincipalKey || !tenantId || !subscriptionId) {
                 throw new Error("Not all values are present in the creds object. Ensure clientId, clientSecret, tenantId and subscriptionId are supplied.");
             }
+            // Attempting Az cli login
             yield executeAzCliCommand(`login --service-principal -u "${servicePrincipalId}" -p "${servicePrincipalKey}" --tenant "${tenantId}"`);
             yield executeAzCliCommand(`account set --subscription "${subscriptionId}"`);
             if (enablePSSession) {
+                // Attempting Az PS login
                 console.log(`Running Azure PS Login`);
                 const spnlogin = new ServicePrincipalLogin_1.ServicePrincipalLogin(servicePrincipalId, servicePrincipalKey, tenantId, subscriptionId);
-                spnlogin.initialize();
-                spnlogin.login();
+                yield spnlogin.initialize();
+                yield spnlogin.login();
             }
             console.log("Login successful.");
         }
diff --git a/package-lock.json b/package-lock.json
index c3e3c9b5..e8b32c12 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -19,6 +19,24 @@
       "resolved": "https://registry.npmjs.org/@actions/io/-/io-1.0.1.tgz",
       "integrity": "sha512-rhq+tfZukbtaus7xyUtwKfuiCRXd1hWSfmJNEpFgBQJ4woqPEpsBw04awicjwz9tyG2/MVhAEMfVn664Cri5zA=="
     },
+    "@babel/code-frame": {
+      "version": "7.8.3",
+      "resolved": "https://registry.npmjs.org/@babel/code-frame/-/code-frame-7.8.3.tgz",
+      "integrity": "sha512-a9gxpmdXtZEInkCSHUJDLHZVBgb1QS0jhss4cPP93EW7s+uC5bikET2twEF3KV+7rDblJcmNvTR7VJejqd2C2g==",
+      "requires": {
+        "@babel/highlight": "^7.8.3"
+      }
+    },
+    "@babel/highlight": {
+      "version": "7.8.3",
+      "resolved": "https://registry.npmjs.org/@babel/highlight/-/highlight-7.8.3.tgz",
+      "integrity": "sha512-PX4y5xQUvy0fnEVHrYOarRPXVWafSjTW9T0Hab8gVIawpl2Sj0ORyrygANq+KjcNlSSTw0YCLSNA8OyZ1I4yEg==",
+      "requires": {
+        "chalk": "^2.0.0",
+        "esutils": "^2.0.2",
+        "js-tokens": "^4.0.0"
+      }
+    },
     "@types/node": {
       "version": "12.7.11",
       "resolved": "https://registry.npmjs.org/@types/node/-/node-12.7.11.tgz",
@@ -36,11 +54,89 @@
         "xpath": "0.0.27"
       }
     },
+    "ansi-styles": {
+      "version": "3.2.1",
+      "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-3.2.1.tgz",
+      "integrity": "sha512-VT0ZI6kZRdTh8YyJw3SMbYm/u+NqfsAxEpWO0Pf9sq8/e94WxxOpPKx9FR1FlyCtOVDNOQ+8ntlqFxiRc+r5qA==",
+      "requires": {
+        "color-convert": "^1.9.0"
+      }
+    },
+    "argparse": {
+      "version": "1.0.10",
+      "resolved": "https://registry.npmjs.org/argparse/-/argparse-1.0.10.tgz",
+      "integrity": "sha512-o5Roy6tNG4SL/FOkCAN6RzjiakZS25RLYFrcMttJqbdd8BWrnA+fGz57iN5Pb06pvBGvl5gQ0B48dJlslXvoTg==",
+      "requires": {
+        "sprintf-js": "~1.0.2"
+      }
+    },
+    "balanced-match": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-1.0.0.tgz",
+      "integrity": "sha1-ibTRmasr7kneFk6gK4nORi1xt2c="
+    },
+    "brace-expansion": {
+      "version": "1.1.11",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.11.tgz",
+      "integrity": "sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==",
+      "requires": {
+        "balanced-match": "^1.0.0",
+        "concat-map": "0.0.1"
+      }
+    },
+    "builtin-modules": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/builtin-modules/-/builtin-modules-1.1.1.tgz",
+      "integrity": "sha1-Jw8HbFpywC9bZaR9+Uxf46J4iS8="
+    },
+    "chalk": {
+      "version": "2.4.2",
+      "resolved": "https://registry.npmjs.org/chalk/-/chalk-2.4.2.tgz",
+      "integrity": "sha512-Mti+f9lpJNcwF4tWV8/OrTTtF1gZi+f8FqlyAdouralcFWFQWF2+NgCHShjkCb+IFBLq9buZwE1xckQU4peSuQ==",
+      "requires": {
+        "ansi-styles": "^3.2.1",
+        "escape-string-regexp": "^1.0.5",
+        "supports-color": "^5.3.0"
+      }
+    },
+    "color-convert": {
+      "version": "1.9.3",
+      "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.3.tgz",
+      "integrity": "sha512-QfAUtd+vFdAtFQcC8CCyYt1fYWxSqAiK2cSD6zDB8N3cpsEBAvRxp9zOGg6G/SHHJYAT88/az/IuDGALsNVbGg==",
+      "requires": {
+        "color-name": "1.1.3"
+      }
+    },
+    "color-name": {
+      "version": "1.1.3",
+      "resolved": "https://registry.npmjs.org/color-name/-/color-name-1.1.3.tgz",
+      "integrity": "sha1-p9BVi9icQveV3UIyj3QIMcpTvCU="
+    },
+    "commander": {
+      "version": "2.20.3",
+      "resolved": "https://registry.npmjs.org/commander/-/commander-2.20.3.tgz",
+      "integrity": "sha512-GpVkmM8vF2vQUkj2LvZmD35JxeJOLCwJ9cUkugyk2nuhbv3+mJvpLYYt+0+USMxE+oj+ey/lJEnhZw75x/OMcQ=="
+    },
+    "concat-map": {
+      "version": "0.0.1",
+      "resolved": "https://registry.npmjs.org/concat-map/-/concat-map-0.0.1.tgz",
+      "integrity": "sha1-2Klr13/Wjfd5OnMDajug1UBdR3s="
+    },
     "deep-is": {
       "version": "0.1.3",
       "resolved": "https://registry.npmjs.org/deep-is/-/deep-is-0.1.3.tgz",
       "integrity": "sha1-s2nW+128E+7PUk+RsHD+7cNXzzQ="
     },
+    "diff": {
+      "version": "4.0.2",
+      "resolved": "https://registry.npmjs.org/diff/-/diff-4.0.2.tgz",
+      "integrity": "sha512-58lmxKSA4BNyLz+HHMUzlOEpg09FV+ev6ZMe3vJihgdxzgcwZ8VoEEPmALCZG9LmqfVoNMMKpttIYTVG6uDY7A=="
+    },
+    "escape-string-regexp": {
+      "version": "1.0.5",
+      "resolved": "https://registry.npmjs.org/escape-string-regexp/-/escape-string-regexp-1.0.5.tgz",
+      "integrity": "sha1-G2HAViGQqN/2rjuyzwIAyhMLhtQ="
+    },
     "escodegen": {
       "version": "1.12.0",
       "resolved": "https://registry.npmjs.org/escodegen/-/escodegen-1.12.0.tgz",
@@ -80,6 +176,64 @@
       "resolved": "https://registry.npmjs.org/fast-levenshtein/-/fast-levenshtein-2.0.6.tgz",
       "integrity": "sha1-PYpcZog6FqMMqGQ+hR8Zuqd5eRc="
     },
+    "fs.realpath": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/fs.realpath/-/fs.realpath-1.0.0.tgz",
+      "integrity": "sha1-FQStJSMVjKpA20onh8sBQRmU6k8="
+    },
+    "glob": {
+      "version": "7.1.6",
+      "resolved": "https://registry.npmjs.org/glob/-/glob-7.1.6.tgz",
+      "integrity": "sha512-LwaxwyZ72Lk7vZINtNNrywX0ZuLyStrdDtabefZKAY5ZGJhVtgdznluResxNmPitE0SAO+O26sWTHeKSI2wMBA==",
+      "requires": {
+        "fs.realpath": "^1.0.0",
+        "inflight": "^1.0.4",
+        "inherits": "2",
+        "minimatch": "^3.0.4",
+        "once": "^1.3.0",
+        "path-is-absolute": "^1.0.0"
+      }
+    },
+    "has-flag": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/has-flag/-/has-flag-3.0.0.tgz",
+      "integrity": "sha1-tdRU3CGZriJWmfNGfloH87lVuv0="
+    },
+    "inflight": {
+      "version": "1.0.6",
+      "resolved": "https://registry.npmjs.org/inflight/-/inflight-1.0.6.tgz",
+      "integrity": "sha1-Sb1jMdfQLQwJvJEKEHW6gWW1bfk=",
+      "requires": {
+        "once": "^1.3.0",
+        "wrappy": "1"
+      }
+    },
+    "inherits": {
+      "version": "2.0.4",
+      "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.4.tgz",
+      "integrity": "sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ=="
+    },
+    "js-tokens": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/js-tokens/-/js-tokens-4.0.0.tgz",
+      "integrity": "sha512-RdJUflcE3cUzKiMqQgsCu06FPu9UdIJO0beYbPhHN4k6apgJtifcoCtT9bcxOpYBtpD2kCM6Sbzg4CausW/PKQ=="
+    },
+    "js-yaml": {
+      "version": "3.13.1",
+      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.13.1.tgz",
+      "integrity": "sha512-YfbcO7jXDdyj0DGxYVSlSeQNHbD7XPWvrVWeVUujrQEoZzWJIRrCPoyk6kL6IAjAG2IolMK4T0hNUe0HOUs5Jw==",
+      "requires": {
+        "argparse": "^1.0.7",
+        "esprima": "^4.0.0"
+      },
+      "dependencies": {
+        "esprima": {
+          "version": "4.0.1",
+          "resolved": "https://registry.npmjs.org/esprima/-/esprima-4.0.1.tgz",
+          "integrity": "sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A=="
+        }
+      }
+    },
     "jsonpath": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/jsonpath/-/jsonpath-1.0.2.tgz",
@@ -99,6 +253,35 @@
         "type-check": "~0.3.2"
       }
     },
+    "minimatch": {
+      "version": "3.0.4",
+      "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.0.4.tgz",
+      "integrity": "sha512-yJHVQEhyqPLUTgt9B83PXu6W3rx4MvvHvSUvToogpwoGDOUQ+yDrR0HRot+yOCdCO7u4hX3pWft6kWBBcqh0UA==",
+      "requires": {
+        "brace-expansion": "^1.1.7"
+      }
+    },
+    "minimist": {
+      "version": "1.2.5",
+      "resolved": "https://registry.npmjs.org/minimist/-/minimist-1.2.5.tgz",
+      "integrity": "sha512-FM9nNUYrRBAELZQT3xeZQ7fmMOBg6nWNmJKTcgsJeaLstP/UODVpGsr5OhXhhXg6f+qtJ8uiZ+PUxkDWcgIXLw=="
+    },
+    "mkdirp": {
+      "version": "0.5.3",
+      "resolved": "https://registry.npmjs.org/mkdirp/-/mkdirp-0.5.3.tgz",
+      "integrity": "sha512-P+2gwrFqx8lhew375MQHHeTlY8AuOJSrGf0R5ddkEndUkmwpgUob/vQuBD1V22/Cw1/lJr4x+EjllSezBThzBg==",
+      "requires": {
+        "minimist": "^1.2.5"
+      }
+    },
+    "once": {
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/once/-/once-1.4.0.tgz",
+      "integrity": "sha1-WDsap3WWHUsROsF9nFC6753Xa9E=",
+      "requires": {
+        "wrappy": "1"
+      }
+    },
     "optionator": {
       "version": "0.8.3",
       "resolved": "https://registry.npmjs.org/optionator/-/optionator-0.8.3.tgz",
@@ -112,17 +295,45 @@
         "word-wrap": "~1.2.3"
       }
     },
+    "path-is-absolute": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/path-is-absolute/-/path-is-absolute-1.0.1.tgz",
+      "integrity": "sha1-F0uSaHNVNP+8es5r9TpanhtcX18="
+    },
+    "path-parse": {
+      "version": "1.0.6",
+      "resolved": "https://registry.npmjs.org/path-parse/-/path-parse-1.0.6.tgz",
+      "integrity": "sha512-GSmOT2EbHrINBf9SR7CDELwlJ8AENk3Qn7OikK4nFYAu3Ote2+JYNVvkpAEQm3/TLNEJFD/xZJjzyxg3KBWOzw=="
+    },
     "prelude-ls": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/prelude-ls/-/prelude-ls-1.1.2.tgz",
       "integrity": "sha1-IZMqVJ9eUv/ZqCf1cOBL5iqX2lQ="
     },
+    "resolve": {
+      "version": "1.15.1",
+      "resolved": "https://registry.npmjs.org/resolve/-/resolve-1.15.1.tgz",
+      "integrity": "sha512-84oo6ZTtoTUpjgNEr5SJyzQhzL72gaRodsSfyxC/AXRvwu0Yse9H8eF9IpGo7b8YetZhlI6v7ZQ6bKBFV/6S7w==",
+      "requires": {
+        "path-parse": "^1.0.6"
+      }
+    },
+    "semver": {
+      "version": "5.7.1",
+      "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.1.tgz",
+      "integrity": "sha512-sauaDf/PZdVgrLTNYHRtpXa1iRiKcaebiKQ1BJdpQlWH2lCvexQdX55snPFyK7QzpudqbCI0qXFfOasHdyNDGQ=="
+    },
     "source-map": {
       "version": "0.6.1",
       "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
       "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
       "optional": true
     },
+    "sprintf-js": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/sprintf-js/-/sprintf-js-1.0.3.tgz",
+      "integrity": "sha1-BOaSb2YolTVPPdAVIDYzuFcpfiw="
+    },
     "static-eval": {
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/static-eval/-/static-eval-2.0.2.tgz",
@@ -131,6 +342,47 @@
         "escodegen": "^1.8.1"
       }
     },
+    "supports-color": {
+      "version": "5.5.0",
+      "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-5.5.0.tgz",
+      "integrity": "sha512-QjVjwdXIt408MIiAqCX4oUKsgU2EqAGzs2Ppkm4aQYbjm+ZEWEcW4SfFNTr4uMNZma0ey4f5lgLrkB0aX0QMow==",
+      "requires": {
+        "has-flag": "^3.0.0"
+      }
+    },
+    "tslib": {
+      "version": "1.11.1",
+      "resolved": "https://registry.npmjs.org/tslib/-/tslib-1.11.1.tgz",
+      "integrity": "sha512-aZW88SY8kQbU7gpV19lN24LtXh/yD4ZZg6qieAJDDg+YBsJcSmLGK9QpnUjAKVG/xefmvJGd1WUmfpT/g6AJGA=="
+    },
+    "tslint": {
+      "version": "6.1.0",
+      "resolved": "https://registry.npmjs.org/tslint/-/tslint-6.1.0.tgz",
+      "integrity": "sha512-fXjYd/61vU6da04E505OZQGb2VCN2Mq3doeWcOIryuG+eqdmFUXTYVwdhnbEu2k46LNLgUYt9bI5icQze/j0bQ==",
+      "requires": {
+        "@babel/code-frame": "^7.0.0",
+        "builtin-modules": "^1.1.1",
+        "chalk": "^2.3.0",
+        "commander": "^2.12.1",
+        "diff": "^4.0.1",
+        "glob": "^7.1.1",
+        "js-yaml": "^3.13.1",
+        "minimatch": "^3.0.4",
+        "mkdirp": "^0.5.1",
+        "resolve": "^1.3.2",
+        "semver": "^5.3.0",
+        "tslib": "^1.10.0",
+        "tsutils": "^2.29.0"
+      }
+    },
+    "tsutils": {
+      "version": "2.29.0",
+      "resolved": "https://registry.npmjs.org/tsutils/-/tsutils-2.29.0.tgz",
+      "integrity": "sha512-g5JVHCIJwzfISaXpXE1qvNalca5Jwob6FjI4AoPlqMusJ6ftFE7IkkFoMhVLRgK+4Kx3gkzb8UZK5t5yTTvEmA==",
+      "requires": {
+        "tslib": "^1.8.1"
+      }
+    },
     "type-check": {
       "version": "0.3.2",
       "resolved": "https://registry.npmjs.org/type-check/-/type-check-0.3.2.tgz",
@@ -155,6 +407,11 @@
       "resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.3.tgz",
       "integrity": "sha512-Hz/mrNwitNRh/HUAtM/VT/5VH+ygD6DV7mYKZAtHOrbs8U7lvPS6xf7EJKMF0uW1KJCl0H701g3ZGus+muE5vQ=="
     },
+    "wrappy": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.2.tgz",
+      "integrity": "sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8="
+    },
     "xmldom": {
       "version": "0.1.27",
       "resolved": "https://registry.npmjs.org/xmldom/-/xmldom-0.1.27.tgz",
diff --git a/package.json b/package.json
index b0b60823..26e25c46 100644
--- a/package.json
+++ b/package.json
@@ -17,6 +17,7 @@
     "@actions/core": "^1.1.3",
     "@actions/exec": "^1.0.1",
     "@actions/io": "^1.0.1",
-    "actions-secret-parser": "^1.0.2"
+    "actions-secret-parser": "^1.0.2",
+    "tslint": "^6.1.0"
   }
 }
diff --git a/src/PowerShell/Constants.ts b/src/PowerShell/Constants.ts
index 2e85a96e..9613db1d 100644
--- a/src/PowerShell/Constants.ts
+++ b/src/PowerShell/Constants.ts
@@ -3,7 +3,11 @@ export default class Constants {
     static readonly moduleName: string = "Az.Accounts";
     static readonly versionPattern = /[0-9]\.[0-9]\.[0-9]/;
 
-    static readonly environment: string = "AzureCloud";
-    static readonly scopeLevel: string = "Subscription";
-    static readonly scheme: string = "ServicePrincipal";
+    static readonly AzureCloud: string = "AzureCloud";
+    static readonly Subscription: string = "Subscription";
+    static readonly ServicePrincipal: string = "ServicePrincipal";
+
+    static readonly Success: string = "Success";
+    static readonly Error: string = "Error";
+    static readonly AzVersion: string = "AzVersion";
 }
\ No newline at end of file
diff --git a/src/PowerShell/ServicePrincipalLogin.ts b/src/PowerShell/ServicePrincipalLogin.ts
index 7760e97c..f4ac6d0c 100644
--- a/src/PowerShell/ServicePrincipalLogin.ts
+++ b/src/PowerShell/ServicePrincipalLogin.ts
@@ -6,9 +6,9 @@ import ScriptBuilder from './Utilities/ScriptBuilder';
 import Constants from './Constants';
 
 export class ServicePrincipalLogin implements IAzurePowerShellSession {
-    static readonly environment: string = Constants.environment;
-    static readonly scopeLevel: string = Constants.scopeLevel;
-    static readonly scheme: string = Constants.scheme;
+    static readonly environment: string = Constants.AzureCloud;
+    static readonly scopeLevel: string = Constants.Subscription;
+    static readonly scheme: string = Constants.ServicePrincipal;
     servicePrincipalId: string;
     servicePrincipalKey: string;
     tenantId: string;
@@ -23,17 +23,53 @@ export class ServicePrincipalLogin implements IAzurePowerShellSession {
 
     async initialize() {
         Utils.setPSModulePath();
-        const azLatestVersion: string = await Utils.getLatestModule(Constants.moduleName);
+        const script: string = new ScriptBuilder().getLatestModuleScript(Constants.moduleName);
+        const outputJson  = await this.getLatestModule(script);
+        const azLatestVersion: string = outputJson.Constants.AzPSVersion;
+        if (!(Constants.Success in outputJson) || !Utils.isValidVersion(azLatestVersion)) {
+            throw new Error(`Invalid AzPSVersion: ${azLatestVersion}`);
+        }
         core.debug(`Az Module version used: ${azLatestVersion}`);
         Utils.setPSModulePath(`${Constants.prefix}${azLatestVersion}`);
     }
 
-    async login() {
+    private async getLatestModule(script: string): Promise<any> {
+        let output: string = "";
+        const options: any = {
+            listeners: {
+                stdout: (data: Buffer) => {
+                    output += data.toString();
+                }
+            }
+        };
         await PowerShellToolRunner.init();
-        const scriptBuilder: ScriptBuilder = new ScriptBuilder();
-        const script: string = scriptBuilder.getScript(ServicePrincipalLogin.scheme, this.tenantId, this.servicePrincipalId, this.servicePrincipalKey, 
-            this.subscriptionId, ServicePrincipalLogin.environment, ServicePrincipalLogin.scopeLevel);
-        PowerShellToolRunner.executePowerShellCommand(script);
+        await PowerShellToolRunner.executePowerShellCommand(script, options);
+        return JSON.parse(output.trim());
+    }
+
+    async login() {
+        let output: string = "";
+        const options: any = {
+            listeners: {
+                stdout: (data: Buffer) => {
+                    output += data.toString();
+                }
+            }
+        };
+        const args: any = {
+            servicePrincipalId: this.servicePrincipalId,
+            servicePrincipalKey: this.servicePrincipalKey,
+            subscriptionId: this.subscriptionId,
+            environment: ServicePrincipalLogin.environment,
+            scopeLevel: ServicePrincipalLogin.scopeLevel
+        }
+        const script: string = new ScriptBuilder().getAzPSLoginScript(ServicePrincipalLogin.scheme, this.tenantId, args);
+        await PowerShellToolRunner.init();
+        await PowerShellToolRunner.executePowerShellCommand(script, options);
+        const outputJson: any = JSON.parse(output.trim());
+        if (!(Constants.Success in outputJson)) {
+            throw new Error(`Azure PowerShell login failed with error: ${outputJson.Constants.Error}`);
+        }
     }
 
 }
\ No newline at end of file
diff --git a/src/PowerShell/Utilities/ScriptBuilder.ts b/src/PowerShell/Utilities/ScriptBuilder.ts
index 8895d227..43b33b85 100644
--- a/src/PowerShell/Utilities/ScriptBuilder.ts
+++ b/src/PowerShell/Utilities/ScriptBuilder.ts
@@ -1,16 +1,50 @@
+import * as core from '@actions/core';
+
+import Constants from "../Constants";
+
 export default class ScriptBuilder {
     script: string = "";
-    getScript(scheme: string, tenantId: string, servicePrincipalId: string, servicePrincipalKey: string, subscriptionId: string, environment: string, scopeLevel: string): string {
-        this.script += `Clear-AzContext -Scope Process; Clear-AzContext -Scope CurrentUser -Force -ErrorAction SilentlyContinue;`;
-        if (scheme === "ServicePrincipal") {
-            this.script += `Connect-AzAccount -ServicePrincipal -Tenant ${tenantId} -Credential \
-            (New-Object System.Management.Automation.PSCredential('${servicePrincipalId}',(ConvertTo-SecureString ${servicePrincipalKey} -AsPlainText -Force))) \
-                -Environment ${environment};`;
-            if (scopeLevel === "Subscription") {
-                this.script += `Set-AzContext -SubscriptionId ${subscriptionId} -TenantId ${tenantId};`;
+
+    getAzPSLoginScript(scheme: string, tenantId: string, args: any): string {
+        let command = `Clear-AzContext -Scope Process;
+             Clear-AzContext -Scope CurrentUser -Force -ErrorAction SilentlyContinue;`;
+        if (scheme === Constants.ServicePrincipal) {
+            command += `Connect-AzAccount -ServicePrincipal -Tenant ${tenantId} -Credential \
+            (New-Object System.Management.Automation.PSCredential('${args.servicePrincipalId}',(ConvertTo-SecureString ${args.servicePrincipalKey} -AsPlainText -Force))) \
+                -Environment ${args.environment};`;
+            if (args.scopeLevel === Constants.Subscription) {
+                command += `Set-AzContext -SubscriptionId ${args.subscriptionId} -TenantId ${tenantId};`;
             }
         }
-        this.script += `Get-AzContext`;
+        command += `Get-AzContext`;
+        this.script += `try {
+            $$ErrorActionPreference = "Stop";
+            $$output = @{};
+            ${command}
+            $$output['${Constants.Success}'] = "true";
+        }
+        catch {
+            $$output['${Constants.Error}'] = $$_.exception.Message;
+        }
+        return ConvertTo-Json $$a`;
+        core.debug(`Azure PowerShell Login Script: ${this.script}`);
         return this.script;
     }
-}
\ No newline at end of file
+
+    getLatestModuleScript(moduleName: string): string {
+        const command: string = `Get-Module -Name ${moduleName} -ListAvailable | Sort-Object Version -Descending | Select-Object -First 1`;
+        this.script += `try {
+            $$ErrorActionPreference = "Stop";
+            $$output = @{};
+            $$data = ${command};
+            $$output['${Constants.AzVersion}'] = $$data.Version.ToString();
+            $$output['${Constants.Success}'] = "true";
+        }
+        catch {
+            $$output['${Constants.Error}'] = $$_.exception.Message;
+        }
+        return ConvertTo-Json $$a`;
+        core.debug(`GetLatestModuleScript: ${this.script}`);
+        return this.script;
+    }
+}
diff --git a/src/PowerShell/Utilities/Utils.ts b/src/PowerShell/Utilities/Utils.ts
index 9a25a72b..1428c6ef 100644
--- a/src/PowerShell/Utilities/Utils.ts
+++ b/src/PowerShell/Utilities/Utils.ts
@@ -1,36 +1,9 @@
 import * as os from 'os';
-import * as exec from '@actions/exec';
-import * as io from '@actions/io';
 
 import Constants from '../Constants';
 import PowerShellToolRunner from './PowerShellToolRunner';
 
 export default class Utils {
-    static async getLatestModule(moduleName: string): Promise<string> {
-        let output: string = "";
-        let error: string = "";
-        const options: any = {
-            listeners: {
-                stdout: (data: Buffer) => {
-                    output += data.toString();
-                },
-                stderr: (data: Buffer) => {
-                    error += data.toString();
-                }
-            }
-        };
-        await PowerShellToolRunner.init();
-        await PowerShellToolRunner.executePowerShellCommand(`(Get-Module -Name ${moduleName} -ListAvailable | Sort-Object Version -Descending | Select-Object -First 1).Version.ToString()`, options);
-        if(!Utils.isValidVersion(output.trim())) {
-            return "";
-        }
-        return output.trim();
-    }
-
-    private static isValidVersion(version: string): boolean {
-        return !!version.match(Constants.versionPattern);
-    }
-    
     static setPSModulePath(azPSVersion: string = "") {
         let modulePath: string = "";
         const runner: string = process.env.RUNNER_OS || os.type();
@@ -47,9 +20,13 @@ export default class Utils {
                 // TODO: add modulepath
                 break;
             default:
-                throw new Error("Unknown os");
+                throw new Error(`Unknown os: ${runner.toLowerCase()}`);
         }
         process.env.PSModulePath = `${modulePath}${process.env.PSModulePath}`;
     }
+
+    static isValidVersion(version: string): boolean {
+        return !!version.match(Constants.versionPattern);
+    }
 }
 
diff --git a/src/main.ts b/src/main.ts
index 86b0ad00..a9e7f461 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -30,13 +30,15 @@ async function main() {
         if (!servicePrincipalId || !servicePrincipalKey || !tenantId || !subscriptionId) {
             throw new Error("Not all values are present in the creds object. Ensure clientId, clientSecret, tenantId and subscriptionId are supplied.");
         }
+        // Attempting Az cli login
         await executeAzCliCommand(`login --service-principal -u "${servicePrincipalId}" -p "${servicePrincipalKey}" --tenant "${tenantId}"`);
         await executeAzCliCommand(`account set --subscription "${subscriptionId}"`);
         if (enablePSSession) {
+            // Attempting Az PS login
             console.log(`Running Azure PS Login`);
             const spnlogin: ServicePrincipalLogin = new ServicePrincipalLogin(servicePrincipalId, servicePrincipalKey, tenantId, subscriptionId);
-            spnlogin.initialize();
-            spnlogin.login();
+            await spnlogin.initialize();
+            await spnlogin.login();
         }
         console.log("Login successful.");
     } catch (error) {