I recently updated to the most recent 1.19 forge version (1.19-41.1.0) to attempt to fix the invisible fishing line bug on my server. Now, the game runs perfectly fine until I try to use the fishing pole, at which point the game crashes and I receive the message shown in the image.

Should be fixed by Aquaclture 2.4.5

Weird question. Was the fishing pole created before you updated Forge, or after? :)

If it was created before, trying crafting a new one and see if it happens with that one as well.