ID:105 Mistake

Hello, I'm new to aternos and recently opened a server to play with my friends. My friend has shown me this and told me that it's perfect, and we'll it is. But when I try to upload a map (Harry Potter map 300mb) It tells me Error Id:105. I've seen someone else post the same thing in the forums, to fix that he renamed the zip folder to 'world', which I did, for me nothing changed. Shortly before the map being fully loaded the error pops up. Please fix this problem if possible, that would be great!