ProjectType project gives "VSSDK1031: Extension error" on build after uninstalling the extension in the experimental instance

[microsoft]

ProjectType project gives "VSSDK1031: Extension error" on build after uninstalling the extension in the experimental instance

[dmihailescu]

under the Project properties go to the VSIX tab.
UNcheck 'Deploy VSIX content to experimental instance for debugging' and build.
If you needed to debug, check it back and build again.

[AArnott]

I believe another workaround is to simply relaunch 'devenv /rootsuffix exp' yourself, and close. After that, I think it works.

[rprouse]

Another workaround is to delete your experimental instance. For example, for Visual Studio 2015, delete the folder

C:\Users\{user}\AppData\Local\Microsoft\VisualStudio\14.0Exp

[drewnoakes]

There's also a shortcut in the start menu to reset the hive, which I find helpful.

[davjs]

Changing the version number in the source.extension.vsixmanifest file is a workaround that doesn't seem all too problematic.

I vote to close this for now, with this information kept for reference.

[GregTrevellick]

You can always reset the experimental instance, although up-ing the version number worked for me.

To reset the experimental instance:
http://www.codeproject.com/Tips/832362/Resetting-the-Visual-Studio-Experimental-Instance
https://msdn.microsoft.com/en-us/library/dd875761.aspx

[yannduran]

Hmm, here we are in 2023 now! I found this issue because I had the very same error and this was the top of the search results. I'm glad this issue was here to help me almost 8 years later.

The weird thing is I've uninstalled the extension that I've been working on many times from the Experimental instance (when my current version number is less than, or equal to the installed version), and I've never encountered this error before. But it occurred today, just as explained.

@AArnott's suggestion of course did the trick, but I used Mads Kristensen's Clear MEF Component Cache extension, but I did it in the instance of VS that I'm developing with, and didn't think to do it in the Experimental instance, as I've never needed to do that before.

Thanks!