Realm upload not working

When trying to upload a new world to a realm, it does the exporting world thing, says initializing upload, and then instantly says an error occurred. I wish minecraft error messages were at least more specific. If this isn’t fixed soon, I won’t continue my realms subscription.

 

The world I’m using was created in 1.16 full release, and has resource and behavior packs. It is about 20 MB. I tried disabling all packs, still didn’t work.