So I had 342 worlds and when I ever I loaded Minecraft, I couldn't join anyone. So I deleted like over 120 worlds and got down to 142. I restarted Minecraft. And it asked for which version to choose. I thought it just saved but no, I chose Oct 21 2020 and it put all 342 worlds back. If you want to know why, Whenever I load up Minecraft it says that there is a network issue. Please fix this.