我最近安装了Visual Studio 2017 RC (15.0.26014.0)，并尝试安装扩展程序。然而，在使用“工具-〉扩展和更新”菜单安装任何扩展程序时失败了。以下是安装日志。
27-Dec-16 10:35:19 AM - Beginning to install extension to Microsoft Visual Studio Enterprise 2017 RC...
27-Dec-16 10:35:19 AM - Install Error : System.IO.FileNotFoundException: Unable to find the specified file.
at Microsoft.VisualStudio.ExtensionManager.ExtensionEngineImpl.GetCurrentSetupInstance()
at Microsoft.VisualStudio.ExtensionManager.ExtensionEngineImpl.PerformSetupEngineInstall(InstallableExtensionImpl extension, Boolean installPerMachine, Boolean isPackComponent, IDictionary`2 extensionsInstalledSoFar, List`1 extensionsUninstalledSoFar, IInstalledExtensionList modifiedInstalledExtensionsList, IProgress`1 progress, InstallFlags installFlags, AsyncOperation asyncOp, IInstalledExtension& newExtension)
Microsoft.VisualStudio.ExtensionManager.ExtensionEngineImpl.InstallInternal (InstallableExtensionImpl extension, InstallFlags installFlags, IDictionary`2 extensionsInstalledSoFar, List`1 extensionsUninstalledSoFar,
IInstalledExtensionList modifiedInstalledExtensionsList, AsyncOperation asyncOp, IProgress`1 progress)
at Microsoft.VisualStudio.ExtensionManager.ExtensionEngineImpl.BeginInstall(IInstallableExtension installableExtension, InstallFlags installFlags, AsyncOperation asyncOp)
at Microsoft.VisualStudio.ExtensionManager.ExtensionEngineImpl.InstallWorker(IInstallableExtension extension, InstallFlags installFlags, AsyncOperation asyncOp)
我检查过并发现相应的VSIX文件位于临时文件夹中（C:\Users\xxxxx\AppData\Local\Temp）