This is to do with Tomcat not being able to load previously serialized web sessions that had been saved on an earlier shutdown. This may be because Tomcat didn’t shutdown cleanly and so session objects got corrupted during serialization.
One way to make this error go away would be to disable session persistence across restarts. You can do this by editing the file CATALINA_HOME/conf/context.xml
and setting the pathname
attribute of the <Manager>
to an empty string. This is well documented in the file for Tomcat 7:
<!-- Uncomment this to disable session persistence across Tomcat restarts -->
<Manager pathname="" />
You should also delete any old session.ser
files from the CATALINA_HOME/work/Catalina/localhost/<appName>
folder whilst Tomcat is shutdown.
This may not be acceptable in your case if session persistence across restarts is needed. In which case further debugging of the issue would be necessary.