TF214007: No build was found with the URI

After making some changes to our build machine, we started getting the following error. I got asked to look into the issue and became immediately confused.

Exception Message: TF214007: No build was found with the URI vstfs:///Build/Build/14365. Either the URI does not exist, or TLR\svcTFSService does not have permission to access it. (type BuildNotFoundForUriException)

I was able to log onto the build machine and hit the PROD URL for build 14365 just fine. So I knew it couldn't be permissions. What was it? I said while scratching my head.

Six months back we migrated our TFS instance from DEV hardware to PROD data center hardware. As part of that process, we updated the DEV's Instance IDs so we didn't run into conflicts when trying to hit either site (we continue to use DEV for testing).

While any new connection to DEV would get the new Instance IDs, the legacy connections on our build servers still had the cached version of DEV's Instance IDs, which just so happen to be our PROD Instance IDs (as expected since we migrated from DEV to PROD).

So what was happing was, when someone was making changes to the build machine, they opened Visual Studio and got connected to DEV by mistake. DEV, using the cached Instance IDs (again which were PROD's), became the active TFS server somehow. So when team Build was firing off, it was actually hitting DEV, which obviously didn’t have a build URI 14365. Thus the error.

To fix this, we deleted the TFS cache on the build server. Then to test it, we purposely logged into DEV and checked our local cache. Sure enough, the new DEV entry in the cache had the new Instance IDs. All was well after that.