Mod version: v3.6.1.0
Forge version: 14.23.5.2854

This issue doesn't make the game crash.
Vanilla cave sounds never play while this mod is installed - only the DS ones play for me. This happens in every modpack I have this mod installed in, such as RLCraft 2.8.2 at https://www.curseforge.com/minecraft/modpacks/rlcraft/files/2935316 , and my own modpack that is currently in alpha testing at https://www.curseforge.com/minecraft/modpacks/overkill .
Would you like me to get a client log? I'm happy to help out any way I can - I'm in the Modded Minecraft and BlameJared discord servers if that would make communication easier. My username is Cephelo#4566.