You may have explored all of the Nether in your Minecraft world, and if you didn’t set it to infinite before the Nether Update version 1.16, you won’t be able to discover the new biomes. For players who already set their Minecraft world to infinite, you can continue exploring your Nether to find new locations you haven’t seen yet to populate with the new update. However, you may need to reset your Nether world to fit in with the latest update and receive the latest content. You can do this without creating a new Minecraft world.
Before you do anything, make sure to create a backup for it, which you can do by clicking on the world icon in the main menu, hitting the edit button, and then click the “make backup” option. The backup goes into the backups folder, and you can find this folder under the same location labeled “backups folder” in the edit menu.
Now, under the edit menu, go to your world folder, and you can access all of your Minecraft folders associated with that world. You need to go to the folder labeled “DIM-1” and then delete it. That folder is the Nether dimension of your world. You want to avoid clicking the other folder labeled “DIM,” which is your overworld on your server.
After deleting the DIM-1 folder, all you have to do now is return to the Nether in your Minecraft world, and everything will repopulate. It should have all of the latest 1.16 material for the Nether Update because everything is connecting to information available in the new files.