The title says it all. Here's the crash log.
java.lang.OutOfMemoryError: GC overhead limit exceeded
Well, I'll see if 3 Gb will work, worry because that's most of my useable gigabytes.
EDIT: I tried it, didn't work.
then allocate more if its still giving an out of memory error
I tried using a vanilla 1.12 version and it worked, so I guess I just need more RAM. I guess my modded builds will go on a regular world.