I had the same problem. It seems that the mycollab.bat script file refers server.port to the MYCOLLAB_PORT environment variable that is not defined in windows environment.
If you edit the script file and change the line
%_EXECJAVA% -jar executor.jar %* %MYCOLLAB_OPTS% -Dserver.port=%MYCOLLAB_PORT%
%_EXECJAVA% -jar executor.jar %* %MYCOLLAB_OPTS%
the var in application.properties file will be used.
I hope it helps
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