title: Failed to install Visual studio extensions .VSIX
body: <p>I'm facing an error while trying to install/update any visual studio extension, I'm running Visual studio 2015 enterprise edition on Windows 7.</p>
  
  <p><a href="https://i.stack.imgur.com/tr6jW.png" rel="noreferrer"><img src="https://i.stack.imgur.com/tr6jW.png" alt="Install Log"></a></p>
  
  <pre><code>12/12/2016 11:35:11 AM - Microsoft VSIX Installer
  12/12/2016 11:35:11 AM - -------------------------------------------
  12/12/2016 11:35:11 AM - Initializing Install...
  12/12/2016 11:35:11 AM - Extension Details...
  12/12/2016 11:35:11 AM -    Identifier         : EntityFramework_Reverse_POCO_Generator..d542a934-8bd6-4136-b490-5f0049d62033
  12/12/2016 11:35:11 AM -    Name               : EntityFramework Reverse POCO Generator
  12/12/2016 11:35:11 AM -    Author             : Simon Hughes
  12/12/2016 11:35:11 AM -    Version            : 2.25.0
  12/12/2016 11:35:11 AM -    Description        : Reverse engineers an existing database and generates EntityFramework Code First POCO classes, Configuration mappings and DbContext.
  12/12/2016 11:35:11 AM -    Locale             : en-US
  12/12/2016 11:35:11 AM -    MoreInfoURL        : https://efreversepoco.codeplex.com/
  12/12/2016 11:35:11 AM -    InstalledByMSI     : False
  12/12/2016 11:35:11 AM -    SupportedFrameworkVersionRange : [4.5,)
  12/12/2016 11:35:11 AM - 
  12/12/2016 11:35:11 AM -    SignatureState     : Unsigned
  12/12/2016 11:35:11 AM -    References         : 
  12/12/2016 11:35:11 AM - Signature Details...
  12/12/2016 11:35:11 AM -    Extension is not signed.
  12/12/2016 11:35:11 AM - 
  12/12/2016 11:35:11 AM - Searching for applicable products...
  12/12/2016 11:35:13 AM - Found installed product - Microsoft Visual Studio Enterprise 2015
  12/12/2016 11:36:48 AM - The extension will be upgraded from version 2.24.0.
  12/12/2016 11:36:48 AM - Found installed product - Microsoft Visual Studio Professional 2015
  12/12/2016 11:36:48 AM - Found installed product - Microsoft Visual Studio Community 2015
  12/12/2016 11:36:48 AM - Found installed product - Microsoft Visual Studio 2015 Shell (Integrated)
  12/12/2016 11:36:48 AM - Found installed product - Global Location
  12/12/2016 11:36:48 AM - Found installed product - ssms
  12/12/2016 11:37:57 AM - The following target products have been selected...
  12/12/2016 11:37:57 AM -    Microsoft Visual Studio Enterprise 2015
  12/12/2016 11:37:57 AM - 
  12/12/2016 11:37:57 AM - Beginning to install extension to Microsoft Visual Studio Enterprise 2015...
  12/12/2016 11:37:57 AM - Upgrading 'EntityFramework Reverse POCO Generator', version 2.24.0 to version 2.25.0.
  12/12/2016 11:37:59 AM - Install Error : System.NullReferenceException: Object reference not set to an instance of an object.
     at Microsoft.VisualStudio.ExtensionManager.ExtensionManagerService.RemoveExtensionAutoUpdateSetting(String extensionIdentifier)
     at Microsoft.VisualStudio.ExtensionManager.ExtensionManagerService.UninstallInternal(IInstalledExtension extension, Boolean forceDelete)
     at Microsoft.VisualStudio.ExtensionManager.ExtensionManagerService.CommitInstalledAndUninstalledExtensions(IEnumerable`1 installedExtensions, IEnumerable`1 uninstalledExtensions, IEnumerable`1 packComponentChanges)
     at Microsoft.VisualStudio.ExtensionManager.ExtensionManagerService.BeginInstall(IInstallableExtension installableExtension, Boolean perMachine, AsyncOperation asyncOp, Boolean enforceCertificateCheckForUpgrade)
     at Microsoft.VisualStudio.ExtensionManager.ExtensionManagerService.InstallWorker(IInstallableExtension extension, Boolean perMachine, AsyncOperation asyncOp, Boolean enforceCertificateCheckForUpgrade)
  12/12/2016 11:37:59 AM - Reverting uninstall of version 2.24.0 of the extension.
  </code></pre>
  
  <p>Any advice????</p>