Slitherine

If airfields are occupied by planes in the hangar, a transport plane with a unit inside will unload it there always on the upper (12 o'clock) hex first what can cause infantry being placed on invalid water tiles. Additional unloaded infantry will be placed clockwise, possibly also on invalid terrain.
If you save and reload afterwards, disembarked infantry on water tiles will be placed in transport ships. As long as you don't reload, infantry will possibly be stuck on invalid terrain until all planes inside the hangar take off.