I thought Alex Caves compatibility was fixed in Alex Caves 2.0 but smth in the nightly build breaks again, my guess is its the dithered transparency thats breaking
On Forge 47.3.7
Minecraft 1.20.1
DistantHorizons-forge-2.3.0-a-dev-1.20.1
NightlyBuild_1.20.1-17b7ee90-2024-10-27T16_13_54-05_00
Alex Caves 2.0.2
Citadel 2.6.0