Help, I've lost virtually all player faces!

Surely this has happened before, but a search didn't reveal much.

I have installed a lot of faces into my game (a facepack that I've been using for years). It was working fine, but suddenly it's gone and all the faces with it. There's still a few faces for players and managers in game, but very few, and very inconsistent. I think it's just the default ones, e.g. Eriedivisie teams still have their players.

I've done all the basic things. Clearing the cache, reloading the skin, reloading the game. But nothing seems to be working.

Any ideas?