I've noticed that multiple times that i've launched the snapshots that the game output says that there are missing sounds for the Husks, Polar Bears, and Strays.

I have an example right here:
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.husk.death
[8:37:25 [Client thread/WARN]: Missing sound for event: minecraft:entity.husk.hurt
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.husk.step
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.polar_bear.ambient
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.polar_bear.baby_ambient
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.polar_bear.death
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.polar_bear.hurt
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.polar_bear.step
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.polar_bear.warning
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.stray.ambient
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.stray.death
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.stray.hurt
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.stray.step
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.wither_skeleton.ambient
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.wither_skeleton.death
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.wither_skeleton.hurt
[8:37:25] [Client thread/WARN]: Missing sound for event: minecraft:entity.wither_skeleton.step

After this, the sound system starts up normally and Minecraft launches.