Thursday, July 10, 2014

Running Visual Studio Tests from a Network Drive

This afternoon I ran into an odd issue with Visual Studio 2013 that ate up an unreasonable amount of my time. I recently set up a new project using the built-in Git source control tools. To keep my project safer I put the repository on my network drive, which gets backed-up regularly. In the future we may get a central server, but for now this is good enough. The code was building and running with no problem until I tried running a unit test. No matter what I did Visual Studio couldn't detect any of my tests. The Test output window said:

------ Discover test started ------
Could not load file or assembly 'file:///U:\Repos\Scheduler\Scheduler\Scheduler.Web.Tests\bin\Debug\Scheduler.Web.Tests.dll' or one of its dependencies. Operation is not supported. (Exception from HRESULT: 0x80131515)
========== Discover test finished: 0 found (0:00:00.5040504) ==========

It took some digging, and a few failed attempts at other suggested solutions, but I finally found the workaround:

  • Open a command prompt and type "setx COMPLUS_LoadFromRemoteSources 1"
  • or
  • Create an environment variable named COMPLUS_LoadFromRemoteSources
  • Set the value to 1
  • Restart Studio

Incidentally, I came across another suggested fix that involved changing a "LoadFromRemoteSources" value in the devenv.exe.config file, but this did not work for me. The Environment Variable did the trick.


  1. Been trying to solve this issue for hours! Finally found this, and it worked for me! Thanks!!


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