I have a Minecraft Java server that I've been running from my own PC. I'm attempting to upload the world from it into my Aternos server, but every time I try, it says 'The selected file/folder is not a valid world.' I've tried uploading the folder and a Zipped version of it, and the same thing happens.
Does anyone know what could be causing it? Is this a common problem with worlds from existing servers?
The existing server is in 1.18.1 so I set the Aternos server to the same version.