World Startup Immediate Crash - Unplayable!

All of my Beta worlds are crashing Minecraft immediately on start up but below in the video is the world I have been playing on all day without issue until I got a pop up message announcing that a bunch of bugs have been fixed... I know this is a Beta and crashes happen but the game is entirely unplayable

To replicate

After the 1.16.55 pop up screen announcing the update, open a world and it will crash