Nah it is the C:\Users\(User)\Downloads folder, it was in a folder inside a folder etc., maybe a few too many for it to handle.
Wasn't aware that it would require Java 16, I don't remember reading anywhere that it needed it and I know past Forge servers haven't required it.
Regardless, all works now! Not having Java 16 was the issue. Thanks for the help
did you look at the log?
because there are a lot of errors
Exception loading blockstate definition for mods: betterendforge, industrialforegoing, futurepack, portality, theabyss, allthemodium, envirocore, advancedrocketry, bettercompat, druidcraft, bloodmagic, mysticalagriculture, jaopca
there are also a few FileNotFoundExceptions
how on earth, did you setup your project?