Visual Studio "Unspecified Error"/Loss of Designer support Workaround

So I lost Visual Studio designer support again, with the beautiful “Unspecified Error” error message. I have determined this is caused by the corruption of some file(s) that is not the solution (.sln) file, not any file checked into vault, and not any file related to ReSharper. I believe it is related to me deleting the obj folder (which I won’t be doing again anytime soon), and I think it has to do with Visual Studio’s source control integration, but that last part may not be the case.

In any case, the relatively simple workaround is to

• Make sure any file you want to keep is checked in,
• Close Visual Studio,
• Delete all files other than your *.sln and ReSharper files (*.resharperoptions files and _ReSharper.* folders),
• Do a GetLatest from inside Vault
• Reopen VisualStudio, and
• Rebuild your solution