Wiian16

I am trying to use the Applied energetics 2 mod for 1.12.2, I have forge 1.12.2 downloaded. But, when I put the .jar file into the mods folder and run Minecraft, it doesn't have the mod in the mods section of the title screen, and when I go back to the folder, it has created a new set of folders inside the mods folder that weren't there before. Does anyone know how to fix this? I am using MacOS High Sierra.