Game version : 1.20.1
Forge version : 47.3.0
Waterframes version : 2.0.10
Watermedia version : 2.0.66

The crash only occurs in multiplayer and not in single-player.
I play on a server with many mods, so the crash may not have been caused by this mod.
When I open my creative inventory, the client crashes (not the server).

net.minecraftforge.fml.ModLoadingException: WaterFrames (waterframes) encountered an error during the done phase
§7java.lang.NullPointerException: Registry Object not present: waterframes:remote

(Yes, it's in french so I translated the sentence here)

Crash report :

crash-2024-07-09_16.58.12-client.txt

your error says waterframes item is missing
and you're connected on a multiplayer server

error is about waterframes is missing on your server
which is very weird, you shouldn't be hable to connect into a server if the server doesn't have WF

I've remade an empty server and I've put the mods back on and I no longer have the problem. I don't think it's the mod, I must have made a mistake the first time.