I have installed a Minecraft map in version 1.16.5. I loaded up the map and everything seems usual but after a while playing, the game seems to "crash" because the chat disappeared. I opened up my inventory and the words were black, and items had no names because they were black as well. I left the game and saw that the menu screen also has been affected, too except for the title. This could happen to any Minecraft maps (not all of them), and could affect your whole Minecraft game. Restarting the launcher can fix the problem. But if you reload the world after you restart the launcher, it will just do the same progress again. The only solution is to delete that map, and put the map that has no saved data in to saves once again.