When trying to start Minecraft, none of the sounds will ever load. Also, Realms doesn't work.

I can't get the log to attach, but it says something like:

[06:28:09] [Client thread/WARN]: Missing sound for event: minecraft:ambient.cave

For all the sounds.
And:
[06:28:10] [Sound Library Loader/INFO]: Starting up SoundSystem...
[06:28:10] [Thread-2/INFO]: Initializing No Sound
[06:28:10] [Thread-2/INFO]: (Silent Mode)
[06:28:12] [Thread-2/INFO]: OpenAL initialized.
[06:28:12] [Sound Library Loader/INFO]: Sound engine started
[06:28:22] [Client thread/INFO]: Created: 1024x512 textures-atlas
[06:28:26] [Client thread/INFO]: Narrator library for x64 successfully loaded
[06:28:27] [Client thread/ERROR]: Realms module missing