A few biomes in nature's spirit and oh the biomes we've gone haven't been playing sound - they should probably all run the desert sound region. Is there an easy enough way I can fix these as I find them? I tried adding stratified desert to the mesa file and it worked, but i broke it when trying to add the others haha. These are just the ones I've found.

drylands

windswept desert

stratified desert - probably could play mesa.

Fixed in the newest version. Thanks for reporting this issue. For some reason desert required water to be around.