KB-2009 Data server fails to start due to invalid license


When attempting to start data server in Appian versions 18.1 or later, the data server fails to start with the following error observed in the watchdog.log:

{"level":"ERROR","time":"YYYY-MM-DDTHH:MM:SS.mmmZ","logger":"watchdog","caller":"Watchdog.java:652","thread":"ForkJoinPool.commonPool-worker-2","msg":"Failed to start RTS-0 engine (port=port)"}
com.appian.data.server.UnrecoverableError: Could not establish WebSocket connection with hostname:port. The target q process exited abnormally. Check for earlier errors (e.g. license or startup errors).

Additionally, the rts-engine.log reports:

'YYYY.MM.DDTHH:MM:SS.mmm host   


The output from the rts-engine.log is seen when the license issued does not match the hostname of the server it is deployed on.


The data server requires a valid k4.lic license file. Generate the q output and compare the hostname from the output to the hostname of the server for which license was requested. If the hostnames do not match, request and install a new license.

Affected Versions

This article applies to Appian 18.1 and later.

Last Reviewed: October 2019