"Overlay Head Parts List" causing crashes on race change

[Blaze69]

I'm working on setting up some races to work with RaceCompatibility in order to make them compatible with vampirism and lycanthropy, as well as prevent the bugs associated with custom races (like some quests being stuck because the game doesn't recognize the player's race and is unable to continue), but I hit a snag with it.

 

I have everything set up as instructed, and it's not the first time I create RC support for a custom race, so I know how things work. The vampire version of the races have the proper keyworkds and configs and everything, and the mod mostly works as intended: the races are added to the appropiate FormLists, the quest bugs are prevented, and the race is properly swapped to the vampire counterpart once the character turns into a vampire. The problem is, if I set the "Overlay Head Parts List" option in the race data for the vampire version, the game crashes when doing the swap.

 

I'm certain it's not caused by anything related with the vampirism scripts, because the crash also happens when I just manually change the race using the SetRace command in the console. Oddly enough, the crash only happens when that flag is enabled, and when the character is of the non-vampire version. So, if the character is XRace and I swap to XRaceVampire, I get a CTD, but if it is XRace and I swap to NordRaceVampire, for example (or any race that is not XRaceVampire), there are no CTDs or anything. Similarly, changing from any other vanilla race into the XRaceVampire works fine as well.

 

This leads me to believe the crash is caused by something related to the "Overlaying" process. Vampire races need to have that flag enabled for the race swap to actually change the eyes to the vampire version, and that's why I tried to add it in the first place. If I turn the flag off, then the swap works flawlessly and vampirism works as intended, but the eyes don't change (and I would like them to change).

 

The patch works as-is without the flag (the loss of vampire-specific eyes would not be nice but doesn't affect the main fucntionality itself), but I would like to know why does the "Overlay Head Parts List" option cause the crash. All of the race's head parts seem to be properly set up and they work fine for both the regular and the vampire versions, it's just changing from one race to another that causes the CTD, so any faulty/corrupted HeadParts are not an option. The crash still happens regardless of which headparts are set up for the vampire race, even if they are exactly the same as in the regular race, so I don't see what could cause it.

 

Any ideas about this?