Glad you figured it out. The other common possibility I will mention to others who come across this thread is that maybe the High Strength Java Crypto isn't installed in the right JRE.
Also the session timeout error on the client-side is fairly generic, for security purposes. Definitely always check the server side logs (or if you are an end user ask your sysadmin to check) if you get in a loop of that client side error keep popping up. The server side logs should have a more descriptive stack trace and error message.
Thanks,
~Josh