Hello, In NSConnection.m, +(NSConnection*)defaultConnection 'newPort' is used uninitialized here. The following line (or something like that) should be added in line 305: newPort = [default_receive_port_class newForReceiving]; I just started to port my first big app to GNUstep: Cenon - it's a software for computer-aided manufacturing. So this is my first input in this group. I really appreciate the GNUstep project. Georg vhf interservice http://www.vhf.de