1.8.9 version crashing

[Ogaro]

Hi

 

I want to install Forge 1.8.9 for the Hypixel Skyblock mod NotEnoughUpdates. I used to have Forge 1.16.4 installed, where I would play survival. I tried installing the 1.8 Forge over the 1.16 Forge, and it didn't work. So, I deleted the file for 1.16 Forge, and that worked, sorta. Now, it loads in 1.8.9, but crashes as soon as the game opens up, with the crash report : 

The game crashed whilst initializing game
Error: java.lang.NullPointerException: Initializing game
Exit Code: -1

Can anyone help me with this?