I am having an issue with the new TFS 2015 Update 2 Gated Builds.
After attempting a check-in the gated build queues just fine, every part of the build is successful until it reaches the last step of "Check in gated changes".
When I look at the log for that step I get:
[Error]The shelveset _Build_5427;Build\ad8fe058-f936-4908-91de-57e7bc6a2f9d could not be found for check-in
When I look at the 'Get Sources' log, I see:
2016-04-01T19:11:12.3062092Z tf get /version:C6213
2016-04-01T19:11:13.2125013Z tf shelve _Build_5427 /replace
2016-04-01T19:11:13.3218610Z Successfully created new shelveset _Build_5427;Domain\BuildServiceUser
I recognize the username as the service user (and have thus redacted it here). It looks like it is trying to find the correct shelveset name, but for the wrong user.
Update 4/20/2016 :
I ended up having to create a brand new project.