I've been working on a little mod for myself, changing certain guard uniforms. Specifically in this case I changed the uniform for Solitude guards using the Creation Kit. Great, it worked like a charm. All guards walking around in their new uniforms. This was two days ago. Been there and back several times all the way until last night. I play Skyrim this morning and the moment I exit Sollitude, all the guards are now naked. Says the uniforms have bad editor IDs yet I'm using standard, vanilla Imperial Light and Heavy armours. The armours themselves haven't been modded in anyway. Balls. Time to roll back to an earlier version of my mod. I remove the esp file and restore my earlier back up. Same problem. The guards are walking around naked. It's also worth mentioning that no new mods have been added since last night.

Any one any ideas?

Oh, I should also mention that using the console to add any armour, whilst adding it to their inventory, does not display. They still appear naked.

Edit: I forgot to mention this happens even when deactivating all the other esp files.

Did you added armors to leveled lists? If so, the additions to leveled lists are dissapear when you load a saved game. Besides, if you do that in a list not adding all the elements to the actor but adding some of the elements randomly you will have a CTD.

I'm having to delete the entire game and start again. Removing all esp files and mod-related textures and meshes, the guards revert back to their original uniforms but their heads are invisible! Something has broke somewhere in the game itself it seems.