Map can't load...size problem?

Hi guys, today I've encountered another problem while trying out some custom maps I made with FF6LE-CE. The game won't load the map, no matter how long I wait, and the current music keeps playing. The exit itself is not the problem, because after changing it to a different target map it worked flawlessly again, so it must have something to do with my custom map.

Strangely, it worked before while my test map was still small in size (256 x 256), but I've enlarged it ever since to the maximum size of 2048 x 2048. After that, the map loading stopped working ingame. I tested multiple custom maps I made, and always saw the same result: maps of a smaller size would load without problem, only the maps that have the max size of 2048 x 2048 won't. The vanilla game doesn't have any maps of that size, but since the editor allows it, I figured it should be ok to use. Or can it be that this size is exceeding the game's RAM? If anyone has ever encountered this, I'd be thankful for advice.