Sorry - just realised I sent this to the ruby list rather than the rails list. R. Rob Lally wrote: > Hi, > > I'm having a problem storing an AR model object in a session. Actually > the problem doesn't seem to be related to storing it in a session. The > problem occurs when the session is deserialised on the next request. > > When the user logs in I pop a User object (an AR model) into the session > and redirect to the homepage. Then I see the following error > > <ActionController::SessionRestoreError: Session contained objects where > the class definition wasn't available. Remember to require classes for > all objects kept in the session. The session has been deleted. (Original > exception: undefined class/module User [ArgumentError])> > > Can anyone shed any light on my problem? > > > Thanks, > > R.