Hi,
the issue here is that you have different number of transitions outgoing from fork and incoming to join. So in fact you are forking into two branches but trying to join three. At this moment I think it is not supported.
So it is not a matter of state5 node. You need to specify how many transitions join should wait for. Just at this to your join node and it should solve your problem:
multiplicity=2
HTH
Maciej
BTW, you should start a new thread for this, just to keep it clean.