I posted SirP answer at (german)
http://bote-forum.square7.ch/wiki/index ... _minorracemy short english translation:
we have around 140 minor races, galaxy size is 30x20 = 600 sectors. at the moment minors are distributed starting top left, first completing line 1...going to down right. If there isn't a minor race left to fill the next system, the error appears. The major race down right has a disadvantage
so best don't set minor density more than 60%, and if it appears, stay on enter key...