I recently started playing modded Minecraft and was having a lot of fun using 1.15.2 but today I decided that I wanted to upgrade to 1.16.3 because of the nether update. I downloaded the correct forge version and a bunch of mods for 1.16.3 and even tested it out before adding the mods into the game folder and it worked fine. But after I added my mods, closed and reopened Minecraft, it would stop responding. I can open the Minecraft launcher and press play and it opens normally but when it tries to load into the main menu screen it stops and gives me the message that it stopped responding and that I can either close it or wait until it does respond. waiting does nothing however as I let it sit for an hour, regularly checking up on it with no movement. and closing it doesn’t change anything. I really need help.

The game created a log file that says what went wrong. It's in %APPDATA%/.minecraft/logs if you're on Windows.

Attach the file named debug.log (if there are multiple, attach the one created most recently), so we can see what the actual problem is.

is this it? it says its from today.

debug-1.log.gz

ok i think i got it, i removed all of my mods from the mods folder and its working now. ill just have to sort through my mods and figure out what it was.

thanks for the help though! i really appreciate it