Ruby on Rails WEBrick Returning Blank Pages

I was trying to access some session info in my Rails application and all of a suddent started receiving HTTP 500 errors from the WEBrick server.  This resulted in completely blank pages throughout the entire application.  It didn’t matter whether or not I was accessing legitimate controllers and actions, EVERYTHING was broken.

I searched around for a while and luckily came up with this link that talks about deleting Rails session files.  After clearing out the session files I was able to run the application again.  I’m not sure exactly what caused the problem, but at least I’ll know for next time.  Hopefully this is an infrequent event that only turns up in my development environment.