No sound + SOLUTION

No sounds being played.

Messages in the log file like this:

[06:48:14] [Client thread/WARN]: File minecraft:sounds/ambient/cave/cave1.ogg does not exist, cannot add it to event minecraft:ambient.cave.cave

and

Client> [07:20:29] [Client thread/WARN]: Unable to play empty soundEvent: meta:missing_sound

I looked in the .minecraft/assets directory, and saw a new SOUNDS (all upper case) subdirectory.

I renamed "SOUNDS" (all upper case) to "sounds" (all lower case) and the sounds started working again.