Downloaded world?

I’m trying to send a world file to my friend but it doesn’t seem to work. We are doing the same thing with the world file. We send it to the saves folder, zip it, unzip it, then just launch minecraft.

It kinda works for me but when they do it, it doesn’t work. We are both on the same version of Minecraft with no mods or optifine, we’re both playing Java. Please help the the world was a realm that me and a bunch of my friends used and they got a trial and want to use the realm themselves so we can continue playing Minecraft.