I have an "old" Minecraft world (vers. 1.15) which I last played in May.

Yesterday (First August 2020) I started a realm to play with friends and uploaded this world. After playing for about 20 min (netherite Farming with beds), we wanted to go to go to bed, but by going to bed, the server crashes instant. I tested it out again by going in the same world without uploading it in the realm (singelplayer). It happened again. I got a lot of damage (full diamond armor and protection IV) And my minecraft crashed. Maybe Minecraft things were in the nether and blows the bed up, but at the same time were in the overword and the game crashes.

Does someone know how to fix this?