According to the crash screen i guess patchouli is the issue i dont know anything about this kind of stuff but heres the crash log https://paste.dimdev.org/raw/bozuhanefo

https://pastebin.com/jPFcY2zr latest.log file

i have just atempted to make a mod pack with nothing but patchouli in it and got similar error

after looking some more into the issue on google it looks like its caused by having it set to jar launcher rather than native launcher which is an issue since the pack wont even start to launch when i have it on native so i guess i have to avoid patchouli when playing modded
unless obviously someone has a solution to the problem

user installed ONLY Minecraft 1.12 + Patchouli mod via twitch and still crashed

https://pastebin.com/sR508WKu

user was able to load without crashing using MultiMC instead of twitch

I believe this issue can be closed