i was working on developing my personal pack with my brand new powerful pc, i updated a few mods and added a few (unfortunately i cannot remember what i added as i just flew through them) and launched the instance.

Upon launching the game crashed and presented the following crashlog: https://pastebin.com/NJ465Nu6

i personally had a look and could not find anything which indicated which mod it was so i turned to discord to ask a mod developer for some help and they THINK it might have been todo with chisel or CTM.
since chisel is usually stable and CTM has been updated five times in the past three days, i think it may have something todo with this mod. i have tried downgrading both chisel and CTM but this does not fix the issue.

ok, i looked through to what mods i may have added and came across the newly released MFR. i disabled it and now everything seems to be working fine. so it was NOT chisel or CTM but infact was mine factory reloaded