How to Fix Unrecognized Guid format in Visual Studio 2015

Question

I'm getting an "Unrecognized Guid format" error when I try to open my project in Visual Studio 2015 on a Windows 10 machine (upgraded from Windows 7).

This did not always occur for me. I originally made VS studio open as administrator (because my project needed it at the time) by following the steps in the anwser here: Can you force Visual Studio to always run as an Administrator in Windows 8? I then decided I wanted to switch back to not having it open as admin. To try and switch back I again ran the compatibility troubleshooter, this time I selected "try recommended settings". After doing this I am now getting the Guid error every time I open my project and I can no longer run it. I even get it if I open VS as admin like I did before.

I even tried uninstalling Visual Studio and reinstalling it but that did not work either.

Answer 1

I am guessing you used to run Visual Studio as Administrator. This did it for me. The answer is to delete the compatibility entry in the registry.

1. Type Windows+R on the keyboard to open the Run dialog
2. Type regedit and press enter
3. Browse to HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers
4. Delete the Visual Studio entry

Answer 2

I fixed this on Windows 10 by using the Troubleshoot compatibility tool. It has to do with an extra checkbox being enabled.

• Navigate to devenv.exe by right clicking Visual Studio from start, click properties, and select "Open File Location...".

• Right click on devenv.exe and select "Troubleshoot Compatibility".

• Click "Troubleshoot Program"

• Uncheck "it worked with older versions of windows"

• Click "Next"

• Click "Test the program"

• Confirm everything opens correctly

• Click "Next"

• Click "Yes, save these settings for this program"