Hello

I recently downloaded forge to use a freecam mod and for some reason when i press f3+b to show hitboxes the game crashes. I tested this on other, non-forge versions and it seems to be a forge only thing. I only have freecam by zergatul and optifine in my mods folder. I already tried downloading a new version of forge, and both mods. Does anyone know what's causing this? 

Forgot to mention: im in version 1.21.8. the crash message i get looks like this:
 

The game crashed: extracting render state for an entity in world
Error: java.lang.NullPointerException: Cannot read the array length because "<local10>" is null

Edited August 7Aug 7 by myth

NEVERMIND, solved it. Gonna leave this up in case anyone else runs into the same problem (unless this is different from reddit and I need to delete it in which case feel free, mods)

Turns out optifine and forge hate each other and removing optifine from my mod folder fixed the issue. guess i'll suffer :,)