| .gif) | AlreadyInstalledException | Exception thrown when the extension to be installed is already present on the system. | 
| .gif) | BreaksExistingExtensionsException | Exception thrown when a conflict is found between the extension to install and an existing extension. | 
| .gif) | DownloadCompletedEventArgs |  | 
| .gif) | DownloadProgressChangedEventArgs | Although this API supports the Extension Manager infrastructure, we recommend that you do not use it because it is subject to change. | 
| .gif) | ExecuteCompletedEventArgs | Arguments consumed by the ExecuteCompleted() event. | 
| .gif) | ExtensionManagerException | Generic exception for working with extension managers and extension manager repositories. | 
| .gif) | Guids | GUIDs used to query the extension manager service and the extension repository. | 
| .gif) | IdentifierConflictException | Exception thrown when the extension to be installed has the same ID as an existing extension. | 
| .gif) | InstallByMsiException | Exception thrown when an extension must be installed by a Windows Installer (.msi) file. | 
| .gif) | InstallCompletedEventArgs | Event arguments consumed by the InstallCompleted event. | 
| .gif) | InstallProgressChangedEventArgs | Event arguments consumed by the InstallProgressChanged event. | 
| .gif) | InvalidExtensionManifestException | Exception thrown when a VSIX manifest is invalid. | 
| .gif) | InvalidExtensionPackageException | Exception thrown when a VSIX package is invalid. | 
| .gif) | InvalidPerMachineOperationException |  | 
| .gif) | MissingPackagePartException | Exception thrown at installation when an expected part of a VSIX package is missing. | 
| .gif) | MissingReferencesException | Thrown when references that are required by the extension are not available on the system. | 
| .gif) | MissingTargetFrameworkException | Exception thrown when the .NET Framework version that is required by the extension is not available on the system. | 
| .gif) | NestedExtensionInstallException | Exception thrown when a nested extension fails to install. | 
| .gif) | NotInstalledException | Exception thrown when an operation is attempted on an extension that is not installed. | 
| .gif) | NotPendingDeletionException | Exception thrown by the RevertUninstall method when the extension to be uninstalled is still installed or has already been deleted from the system. | 
| .gif) | PathConflictException | Exception thrown when another extension is already installed on the target installation path, as defined by the VSIX manifest. | 
| .gif) | ProxyCredentialsRequiredException | Exception thrown from the IVsExtensionRepository method when a web service call requires proxy authentication. | 
| .gif) | RequiresAdminRightsException |  | 
| .gif) | SystemComponentException | Thrown when an attempt is made to install an extension that is a system component. | 
| .gif) | VSEdition | List of supported editions of Visual Studio that may be targeted by an extension. |