Combat Commander Europe No Die rolls possible

Hi Guys!
Me and a friend tried to play Combat Commander Europe last weekend. After a short while my opponent couldn’t make any die rolls anymore. There seems to be some kind of technical problem that we don’t understand, but maybe we just did not understand something. Could you please give us a hint? We have just started to play and it is such a great game. Looking forward to your reply.
The Vassal version itself is 3.2.17
Combat Commander Europe Modul Version 2.3., it says in the opening menu that vassal 3.2.6. is used
Java Version is 8 Update 241