Hi,
Using Minecraft 1.21.4, Fabric 0.16.10 and NotEnoughAnimations causes the game to crash.
Here is the logs:

NotEnoghAnimations.txt

Before you open more issues, same thing as with waveycapes, and seems like 3d skin layers too. You downloaded the wrong version of the mods.
waveycapes-fabric-1.5.1-mc1.21.jar
skinlayers3d-fabric-1.7.4-mc1.21.jar
notenoughanimations-fabric-1.9.2-mc1.21
RyoamicLights-fabric-0.2.11+mc1.21.1.jar
fabricskyboxes-0.7.4+mc1.21.jar
etc, make sure to download the correct 1.21.4 files when available/that the file is marked to work for 1.21.4.

Ok I'll check again

I checked and these were the plugins that were old and had to be disabled (I haven't checked if they work with the latest version or not):
[✘] enhanced_attack_indicator-1.1.0+1.21.jar (disabled)
[✘] fabricskyboxes-0.7.4+mc1.21.jar (disabled)
[✘] fsb-interop-1.4.0+mc1.21-build.54.jar (disabled)
[✘] ObsidianUI-fabric-0.2.9+mc1.21.1.jar (disabled)
[✘] RyoamicLights-fabric-0.2.11+mc1.21.1.jar (disabled)