Most of the warnings are about sound events.

 
12:37:21.176
Missing sound for event: minecraft:item.bucket.fill_tadpole
12:37:21.178
Missing sound for event: minecraft:music.overworld.deep_dark
12:37:21.179
Missing sound for event: minecraft:entity.tadpole.eat
12:37:21.179
Missing sound for event: minecraft:entity.tadpole.grow_up
12:37:21.179
Missing sound for event: minecraft:entity.tadpole.step
12:37:25.488
Shader rendertype_entity_translucent_emissive could not find sampler named Sampler2 in the specified shader program.
12:42:20.097
Missing sound for event: minecraft:item.bucket.empty_tadpole
12:42:20.097
Missing sound for event: minecraft:item.bucket.fill_tadpole
12:42:20.109
Missing sound for event: minecraft:music.overworld.deep_dark
12:42:20.110
Missing sound for event: minecraft:entity.tadpole.eat
12:42:20.110
Missing sound for event: minecraft:entity.tadpole.grow_up
12:42:20.110
Missing sound for event: minecraft:entity.tadpole.step
12:42:21.062
Shader rendertype_entity_translucent_emissive could not find sampler named Sampler2 in the specified shader program.
12:43:49.792
Can't keep up! Is the server overloaded? Running 4270ms or 85 ticks behind
12:47:27.466
Can't keep up! Is the server overloaded? Running 2034ms or 40 ticks behind
12:48:34.242
Unable to play empty soundEvent: minecraft:entity.salmon.ambient