Tomcat save server state when shutdown. Thus, improper shutdown and save state may cause the following error when you start your tomcat server
Feb 21, 2011 6:01:18 PM org.apache.catalina.session.StandardManager doLoad
SEVERE: IOException while loading persisted sessions: java.io.EOFException
To solve this issue, all you need is to delete the content in the your_tomcat/work directory and restart your server.
Basically, tomcat is trying to look for and read in SESSION.ser. In general, the work directory is working directory for tomcat which reside the JSP and their resulting compiled class files.