Hey I get this error. I actually had people get the same error when I was trying to export my game. What I ended up doing is I clicked a button saying to add pck file to my game then I exported it like that. Then I put the exported file in a folder with a copy of my scenes folder I just kept it the same name "scenes" and then that seemed to work fine, so I zipped that whole thing up and gave it to people.
I'd love to play your game once you get this sorted! (and help you get it sorted)