Are Minecraft Mods 1.14 compatible with 1.14.4?
You must reinstall.
What?
You have to learn right German ^^
Sorry, I'm a Russian immigrant. I say, reinstall the entire Windows computer.
Yes, he should use Linux, maybe he can try Wine.
Java is platform independent, so he can play Minecraft on Linux without Windwow's virtual machine.
So far as I do not know. Optifine can be, but worldedit for example does not work. The version is not out there that long. Do you have to look at the pages where the mods are available for download.
Some mods that concern, for example, no new functions or blocks should go anyway