We have recently upgraded to TFS 2015 Update 4. When I tried to do a build, I am getting the following error:
There are issues with the request or def
You could double check if you are missing some capabilities such as VSTEST_15.0 for the build agent.
Settings- Agent Queues- Agent Pool - Agent- Capabilities
If the test related capabilities are missing, you could try to reregister the build agent. Or manually add the capabilitie by select +.
Recently I had the same issue: installed VS2017, configured build agent, visualstudio and msbuild capabilities missing.
Try installing VS2015 next to VS2017. Re-configure the build agent after this (in my case, I completely removed all the old _diag, _work and settings.json data as well). This fixed the issue for me, the missing capabilities were now recognized.
I was getting the same error out of the blue and it was running fine the previous week. Restarting the build agent service resolved the error for me