When requesting an Open in Excel a pop-up shows this error.

TF400051: Cannot process URL when attempting to open a query in Excel….

Azure DevOps

This is maybe your installed Visual Studio (VS) that is a lower version recently. Example. Before you’ve install VS 2017 and then VS 2019, but recently you’ve install VS 2010 due to a legacy project support. That sometimes changes a registry that produce this error.

To fix it follow the following:

1. Open RegEdit
2. Navigate to
   
   Computer\HKEY_CLASSES_ROOT\tfs\shell\open\command
   
3. Change the value to the following
   
   C:\Program Files\Common Files\Microsoft Shared\Team Foundation Server\15.0\TfsProtocolHandler.exe “%1”
   
4. Save the changes.
   

That’s it. Try exporting again and it should work now.

God Bless!
Thanks,
Thomie