Hi, In the Twisted docs it is claimed that in order to propagate exceptions over PB: "The only special thing you do is to define your Exception subclass by deriving it from pb.Error. " This seems simple enough, but I am using PB to adapt a general service that doesn't use pb.Errors (as the service is also adapted to other protocols). How can one transform a regular Exception to a pb.Error? The following does not work: def remote_foo(self, f): d = self.service.foo(f) def raiser(): raise pb.Error('I pbfailed') d.addErrback(lambda reason: raiser()) # reason is an Exception, not a pb.Error! return d In this case, the server still complains about an unhandled exception. Any thoughts about how to do this? Thanks Brian