I lost all of the 20w51a features.  All of my villagers and pets with name tags are gone.  All dirt blocks that were made into paths are gone.  I lost all of the wood frames holding items.  Alything on the frames is missing and my stand with items on it are missing.   Some villages far away are completely missing except for hay bales.  This patch destroyed my game.  I had a big village and was starting to go tot he end.  I am not sure how to revert to an old file or version.