(The Version 1.16.4 IS NOT broken i just had to pick a Version!!!)

For some odd reason when trying to open a Forge Version (e.g. 1.12), Minecraft doesn´t even open. Insead the Launcher open a few seconds after closed leaving the following message:
An unexpected issue occured and the game has crashed. We´re sorry for the inconvinience. Exit Code: 0. I don´t know why but it works for everyone exept for me! Please give a Feedback. It could also be fixed by reinstalling Minecraft since i haven´t tried that yet but im scared of my folders (my worldfolders) getting deleted because this already happened once when i logged out and back in... so please somebody help. Btw It can´t be my PC since it never had any Problems before other than that my space is running out.