Microsoft.VisualStudio.ExtensionManager.InvalidExtensionPackageException: The file is not a valid VSIX package.

[vvidov]

Hello, I have build solution with VS2015. When I start it I have that error

30.08.2017 08:54:15 - Microsoft VSIX Installer
30.08.2017 08:54:15 - -------------------------------------------
......
30.08.2017 08:54:47 - PKGDEF Information: InitializeCache: Post initializing cache
30.08.2017 08:54:47 - PKGDEF Error: Nothing to unlock for PkgDef mutex, PKGDEF: 8000FFFF
30.08.2017 08:54:47 - PKGDEF Information: PkgDefManagement startup complete
30.08.2017 08:54:47 - PKGDEF Information: Shutting down pkgdef registry
30.08.2017 08:54:47 - PKGDEF Information: PkgDef registry shutdown complete
30.08.2017 08:54:47 - Initializing Install...
30.08.2017 08:54:48 - Microsoft.VisualStudio.ExtensionManager.InvalidExtensionPackageException: The file is not a valid VSIX package.
bei Microsoft.VisualStudio.ExtensionManager.InstallableExtensionImpl.ReadVSIXManifestFromPackage(Stream stream, CultureInfo preferredCulture)
bei Microsoft.VisualStudio.ExtensionManager.InstallableExtensionImpl..ctor(String path, CultureInfo preferredCulture)
bei Microsoft.VisualStudio.ExtensionManager.ExtensionEngineImpl.CreateInstallableExtension(String extensionPath, CultureInfo preferredCulture)
bei Microsoft.VisualStudio.ExtensionManager.ExtensionEngineImpl.CreateInstallableExtension(String extensionPath)
bei VSIXInstaller.App.GetInstallableData(String vsixPath, Boolean isRepairSupported, IEnumerable1& skuData) bei VSIXInstaller.App.Initialize(Boolean isRepairSupported) bei VSIXInstaller.App.Initialize() bei System.Threading.Tasks.Task1.InnerInvoke()
bei System.Threading.Tasks.Task.Execute()