Limbo?

[caravel]

Yup. Nice, I never knew that. My solution always was to save and reload the game. That works, too. And it gives you just enough time to put fresh bucket of coffee on the stove.

I never knew that either, so it looks like a trade.

In some cases the ransomed army in it's entirety won't fit into the fort so the only solution was to move them to another province where they would fit in. The obvious solution now is to first try to move them into the fort, failing that: save and reload.