I upgraded my Ubuntu installation and was having problems getting my web applications to start correctly in Tomcat 5.5. I'm not using the standard location for the webapps.

I was getting ajava.security.AccessControlException.

I had to modify my /etc/tomcat5.5/policy.d/50user.policy and had to add this:

grant codeBase "file:/home/timb/webapps/-" {
permission java.security.AllPermission;
};