Cannot find custom tool on this system, even though it is there

Question

I'm trying to use an in-house custom tool that generates C# code from XML in Visual Studio.

The last time I successfully used the tool was about a month ago, since then I've updated from Windows 8.1 to Windows 10 and have also updated Visual Studio 2015 from Update 2 to Update 3. I have colleagues who were using Windows 10 and Update 3 before they installed the tool for the first time and there are no problems finding the tool for them.

There have been no changes to the tool made since updating Windows and Visual Studio.

When I tried to use it today I'm seeing the error

"Cannot find custom tool on this system".

I've tried uninstalling and reinstalling my tool, as well as calling devenv /setup, as well as deleting and readding the extension gallery for my custom tool. I've also tried repairing Visual Studio, to no avail.

I've checked the registry and I can see the key for the tool there.

Has anyone else experienced the same issue, or got any suggestions for other things I can try?

Thanks a lot!

Answer 1

The reason why the custom tool couldn't be found is because the strong name wasn't being verified.

I fixed the issue by running sn -Vr *,(missing public key) to add the assembly to the verification skipping list.

I don't know why the custom tool could be found prior to the Windows 10/Visual Studio upgrade. My best guess is that the verification list previously contained it and was lost whilst upgrading to Windows 10.