After you manage to run the installing program and it fails, please try pkcon updating BEFORE you restart. You may encounter an error with a library (i don't remember its name) that needs to be removed and pkcon has to finish the updates, or your plasma will be broken and you'll be stuck in text-based OS fixing the same problem, except you can't use internet or anything on the same device. Managing it with Konsole while booted helps a lot.