Installing extension problem

Copper Contributor



I have clean installation of Windows Server 2022 (include all updates) and Azure DevOps Server 2022 Patch 3.

I am trying to install some extensions from Marketplace (I have tried many different extensions), but I am getting the same validation error:


Extension validation error


Could not load file or assembly 'System.Web.Mvc, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.


Has anybody encountered this problem ? 

Thank you

2 Replies



Hi, thank you for reply.

I red more articles like this one, but Azure DevOps is not my project. I can not change references and recompile it.