It was fine until I installed the RealLight mods, so I presume that they are the cause.
My current load order from top to bottom is:
RealLight- Cities
RealLight- CitiesixT
RealLight- Dungeons
RealLight- Weathers
Visible map markers
Resurrection
Better city entrances
Immersive citizens- AI overhaul
Whiterun supreme
Riften supreme
Rain and snow FX
Skyrim is windy
Dense grass
Water- water and terrain enhancement
Project hippie
How should my load order look? because I'm unsure and I would like to keep these mods
Thanks
EDIT
I think I figured it out... I didn't realise that I had surreal lighting installed, but when I uninstalled it, the game stopped crashing. As soon as I reinstalled it, the crashing started again. So I'm guessing that surreal lighting isn't compatible with the RealLight mods