Non-existing class or faction freezes the game
While this is a "bug" in the Ashes of Apocalypse Mod, and can be easier fixed by adding an additional class, this means that the original AoA is not playable by default.
It seems that Morrowind will work around the missing Class by mapping it to the first in the Class list.
Can we do this in OpenMW as well? This would fix AoA and any number of other mods.