Me and my friend want to play MC together with mods. We have exactly the same mods in the folder and I also launch MC, but my friend states: It looks like you're using an unsupported version of the game. What can you do about it?
The error code: The game crashed while there was a severe problem during mod loading that has caused the game to fail
The game crashed while there was a severe problem during mod loading
Error: cpw.mods.fml.common.LoaderException: java.lang.NoClassDefFoundError: scala / collection / Seq
Maybe he has an older / too old Forge version (I do not mean 1.12 / 1.12.2 etc. In the screenshot you can see the behind 1.12.2 another Forge VErsion) If that does not help. Could you test it out, uninstall all Java versions and install the latest one. If that does not help, you can delete the .minecraft folder (you can find it by pressing the Windows key + R, then a small window opens, where you enter then% appdata%, then another window opens with folders Before you should copy something like texture packs / worlds (saves) / mods into a separate folder, so you do not lose them after you have deleted the entire folder you have to log in MC again.
