The source of this error is Tomcat session persistence,
which requires all attributes in the session be Serializable.
Therefore, the workaround is to disable Tomcat session persistence
. This can be done in a "context.xml" configuration file in Tomcat conf directory:
Code: Select all
<!-- Default set of monitored resources -->
<!-- Uncomment this to disable session persistence across Tomcat restarts -->
<Manager pathname="" />
However, this was not enough - there is a tag in web.xml, which has to be commented out. Otherwise it overrides the settings in context.xml.