After upgrading the WebApp won't start and the following error was seen in <SPECROOT>/webtomcat/bin/logs/webswing.log
Caused by: org.webswing.exception.WsInitException: Invalid system property webswing.configFile: File /opt/spectrum/webtomcat/bin/webswing.config or /opt/spectrum/webtomcat/bin/webswing.config not found.
23.3.4
The following lines were missing in <SPECROOT>/webtomcat/webswing/webswing.config
webswing.warLocation=../webapps/spectrum.war
webswing.configFile=../webswing/webswing.config
webswing.tempDirBase=../webswing/tmp
webswing.propertiesFile.admin=webswing-admin.properties
webswing.useGrizzlyWebsocketContainer=true
Add the following lines to the bottom of <SPECROOT>/webtomcat/webswing/webswing.config
webswing.warLocation=../webapps/spectrum.war
webswing.configFile=../webswing/webswing.config
webswing.tempDirBase=../webswing/tmp
webswing.propertiesFile.admin=webswing-admin.properties
webswing.useGrizzlyWebsocketContainer=true
Then restart webtomcat. After doing that the WebApp will successfully open