The attached (see Attachments tab) is the updated build agent. It doesn't fix your problem but has additional logging capabilities.
Please, unpack it and put into the 'update' directory on the build server (latest Agra EAP 1461). Your agent should be upgraded shortly.
Please ensure that file idea_dist.jar is present among the plugin jars. Take it from the previous installation. I didn't put it into this zip because of its size.
When your agent is upgraded run your build and send me teamcity-agent.log or its portion related to this build. The log file is located in buildAgent/logs directory.