I don't know what my issue is, but I can't get Optifine to work. When I try to run the .jar it pops up some sort of window for a split second and then it goes away and nothing happens. When I try to use Magic Launcher it says there are no mod files. I am using Minecraft Version 1.12.2
Someone please help.
EDIT: Nvm, I got it to work by using Forge. Thank you anyways.