The debugger cannot continue running the process

Regular readers know I like blogging about error messages that aren't well covered in Google, so I wrote this so Google will know the answer for the next person.

I just had the following error message when trying to build a website in Visual Studio 2008:

The debugger cannot continue running the process. The project file ' ' has been renamed or is no longer in the solution.

This was due to a project being removed from the solution that had been used as a project reference in a website project. There was no apparent way to fix this in the IDE, so I cracked open the .sln file in Notepad 2.

About the sixth line down was the following:

ProjectReferences = "{8F64A45E-142E-4235-9F43-D7EB556B4C77}|DeletedProject.dll;"

As that was the name of the project, I removed the line, saved, and reloaded in VS. The website then built.