Minecraft 1.12.2

Obfuscate is a Library, which allows easier codding with player body parts or simply put "animating".
The RFP2 mod or Real First Person has preset settings of how the models / slots should look like and such. While that is completely fine, if you add mods/library that override those settings, will most certainly brake it, as this mod does.

MrCrayfish's vehicles mod is dependable with this library and uses it for many body parts positioning,
one of which is the head while inside vehicles.

Example when using RFP2 with obfuscate needing mods (MrCrayfish vehicle mod):

issue is fixed here https://github.com/JacksonPlayz/Obfuscate/tree/mixin . You can compile yourself or wait for MrCrayfish to pull this fix