Can't launch 1.12.2

[eevee73]

I'm pretty sure the problem is that my jar file is missing and I only have the json file. I tried reinstalling and it just gives me the json file. the error is vague. just "it looks like an unexpected issue occurred. we are sorry for etc

 

edit: it may be optifine, lemme see

edit 2:it was optifine

Edited June 12, 2019 by eevee73

[Ugdhar]

Optifine is pretty specific about the versions of forge it is compatible with, checking optifine's changelog will usually tell what forge build it works with.