I'd appreciate if you could turn on debug.override in LiquidUU.cfg and get me the stack trace that will be printed when the Forestry integration fails to load. Debug mode is a little chatty, so you might want to turn it off afterwards, but if you get me that stack trace I can maybe do better than guessing. Maybe.
Something I noticed: This error isn't happening in single player play. In single player mode the squeezer continues to operate just fine. This is the error i'm getting on the server when it launches with identical mod lists and configurations.
I also see an odd error about extrabees being unable to see the forestry configuration due to some java reflection error. I think that error was in the other server log I posted as well. Related?