NeoForge version: 21.1.93
Twilight Forest version: 4.6.2941
Link to crash log: https://gist.github.com/SgtMorrigahnGaming/6d777a3c679a70e18f231adc6dbfb5dc

Steps to reproduce:

1. Do all the bosses to open up Dark forest. Venture in until you find the area where you have to descend to the three knights..

What I expected to happen: See the area as it's normally is

What happened instead: Weird rainbow color stripes covering everything below ground level. Screenshot here:

https://imgur.com/a/2w8AEG8

Edit: I forgot to mention, I'm playing the official ATM10 pack

Hey, I also had this issue, I only turned bloom off because it was too much, also official ATM10, any suggestions would be appreciated.

If you go into creative mode the lines do not show up, seems to only effect survival, dunno if thats helpful info... Second image is in Creative mode same POV...

Ok, I had to cheese it to try figure it out somehwhat, in creative , I got the boss to low HP then switched back to survival, I fogot to place the trophy till after the fight, I placed a trophy on the pedestal after the fight, the area has a mining prevention so you cant cheese it in survival, obviously them stripes arnt supposed to be seen, I think theyre anti mining indicition or something, I could be wrong, so initially killing the boss prior to placing the trophy is unintended, so is the glitch, jumped back into survival after I placed the trophy because I couldnt see and the stripes are gone, best I can understand anyways.

Can confirm this issue is apparent in 4.6.2941. There are giant rectangles of red, yellow, green, and black that projects down ALL squares at y=2 in the dark forest biome, seems specifically around the Phantom Knight Barrows. And they seem to also face you. It seems it's TRYING to render the intended "Green floating square" "Ya not supposed to be here" indicator, but instead in most instances, it's failing miserably

This is what's supposed to happen, and happens in specific instances:
https://i.imgur.com/33goeYV.png
This is what MOST of the time is happening
https://i.imgur.com/CPe98FZ.png

I currently have a feeling Iris/Sodium might be to blame for this, but it could be the renderer overloading due to a sheer ton of this effect being used. Whatever it is, my stomach is now upside down after having to walk through it trying to find the pedestal to clear it.

A suprising workarround that worked for me was creating a FTB Chunks Map waypoint on myself while at the entrance of the Stronghold. For some reason that removed the giant rectangles

duplicate of #1769 - we're still trying to track down what exactly is causing this to break but its tricky to figure out what