Inability to load 1.16 pre-release worlds after closure

I cannot load into a world that i created after the 1.16 pre-release update. i have no idea why but whenever i try to load the world it tells me there are experimental settings in the world, when there aren't, and tells me to create a backup. when i click the button i get a crash notification that tells me "The game crashed whilst mouseclicked event handler
Error: java.lang.IllegalStateException: Lock is no longer valid" i don't know if this is a bug or not but any world i create cannot be loaded. even if i touch nothing that could be considered an experimental setting i cannot load the world.