Teamcity agent in disconnected state (Agent has unregistered (will upgrade))

Question

Teamcity build agent in disconnected state (Agent has unregistered (will upgrade)) on the server UI. The build agent service was in hung state tried reboot but still didn't work so manually upgraded the TC build agent with the version server had. Rebooted the build agent service. Still disconnected. Please suggest.

Answer 1

I ran into this issue and found a solution, but I'm going to make a few assumptions about your setup.

This fixed an issue I had with a TeamCity build agent on Windows and running as a user account (as opposed to a System Account).

1. Stopped the TeamCity service and changed the account to a System Account
2. Started the TeamCity service and waited about 10 minutes for the upgrade to complete. The build agent showed up in the "Connected" agents tab indicating a successful upgrade.
3. Stopped the TeamCity service and switched back to the user account
4. Started the TeamCity service

The other option is to grant the user account permissions to start/stop services, but I went this route instead. See this article for those steps.