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On a rare occasion of the TeamCity server or agent process terminating unexpectedly with no apparent reason, it can happen that this is caused by a Java runtime crash.
If this happens, the Oracle JVM regularly creates a file named hs_err_pid*.log in the working directory of the process. The working directory is usually <TeamCity server or agent home>/bin Under WIndows when running as a service it can be other like C:\Windows\SysWOW64. You can also search the disk for the recent files with "hs_err_pid" in the name.
See also Oracle documentation, related the Fatal Error Log section in the document.
Please send this file to us for investigation and consider updating the JVM for the server (or for agents) to the latest version available.
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