I'm using TeamCity 4.5 and, as an experiment, I made a change to the config file on the build agent (adding a new configuration value - don't ask). After I did that, the server claimed that the agent had unregistered itself. So I restored the config file to its original state and waited for the agent to recover. It didn't. I restarted the build agent service - still no reconnection. In desparation, I "Removed" the agent on the TeamCity server then restarted the build agent service.
Can someone help me recover my agent? Is there a way to force an agent to tell the server that it's ready to be used?