Hi Howard, More information. The actual error is
"bad frame_type in StackMapTable" and is thrown from javassist.bytecode.StackMapTable.stackMapFrames(int,int). Not sure whether this helps, but it looks as if the stack is messed up. There is a try {...} finally{..} in the code, and if I remove this it runs through. I've spent several hours trying to produce a small test case (the actual site includes a 500k line internal library), and, even though it looks very similar it runs through fine. I'll continue trying to produce a test case, but in the meantime is there anything I can do to identify the cause? Thanks, Adriaan