I was with a friend. We were in the end, we broke all of the end crystals. We went to the bedrock thing (where the dragon stands on for a few seconds) then my friend got kicked fromthe server and everything froze; i could still walk and place blocks and break blocks, when i would try to kill myself it wouldn't let me, when i would drop items they would vanish into the air, when i would open the settings menu and tried to put the game into creative (or anything else) it would work, and finally when i would leave the game, it would be stuck in "saving the world" which means that i would have to close out of the application and after that, the world was still broken. Normally, i wouldn't report this but me and my friend worked really hard in this world and we don't want to start a new one. If you have anything that could work to fix the world, please tell me your help would be appreciated.
What type of server are you and your friend using? The default server software? SpigotMC? Realms? It might be a bug related to the server software and not the game.