My minecraft looks purple!

When I had Minecraft 1.16.40, everything was normal, and I wanted to move on to the beta version, to test the news, but when I entered a world, everything looked purple!. I thought it was the "Custom Biomes" option but it wasn't, after I uninstalled Minecraft and reinstalled it, but I'm still with the problem. I don't want to keep version 1.16.40, but if the beta doesn't work, I'll have to exit the beta. HELP ME PLEASE!!