I have updated our development installation of Galaxy. This wasn't done for a long time, so it was a quite old version. 

The update is done from galaxy-central. 

I did hg pull, hg update and a db update. All that without errors. 

But when I now try to start Galaxy, I get the following: 

Traceback (most recent call last):
  File "/galaxy-dev/lib/galaxy/web/buildapp.py", line 82, in app_factory
    app = UniverseApplication( global_conf = global_conf, **kwargs )
  File "/galaxy-dev/lib/galaxy/app.py", line 71, in __init__
    self.security = security.SecurityHelper( id_secret=self.config.id_secret )
  File "/galaxy-dev/lib/galaxy/web/security/__init__.py", line 36, in __init__
    self.id_cipher = Blowfish.new( self.id_secret )
ValueError: Maximum key size is 448 bits

I'm totally lost on this one. Does anyone have an idea or a hint on where to start? It would be highly appreciated! 

Thanks a lot!