Ah young Padawans! You all seem to be overlooking the most obvious: the number of heirs that you have is linked directed to the number of provinces (cities) that you own. I think that you can have a number of generals is equal to the number of completely controlled provinces plus or minus 2 or 3.

As a result. It is entirely possible that you have Maxed Out the number of family members that you can have and the game simply refuses to spawn any more.

Think of it as a servere empire wide lack of... of... of something that rings true with the above statements and is really comical to end the post with.

*phew*

That was lucky, I don't think anyone noticed that you make a total cock up of that...