The project file XXX cannot be opened.

Problem

You get this error when attempting to access your application in Visual Studio .NET.

The project file XXX cannot be opened.

The project type is not supported by this installation.

This error occurs when the appropriate service pack for Visual Studio has not been installed.

Solution

Install Visual Studio 2008 Service Pack 1 (SP1) or later.

See Also

Part VII:  Troubleshooting Applications

Application Generation and Compilation Error Messages