If you had a process creating that zip that involved creating "?" characters in file names, maybe there were other issues as well, when the zip was created. Did you look at this zip with a regular zip view app, to check if all that you wanted to be in the zip is in the zip - and nothing else, like system files needed for your system, but not for the upload?
Thanks for the reply, i had some files with no extensions when i saved the website from chrome "as HTML", i cleaned up all the files but guess i missed a few. Even though having files with no extensions was fine for running the index file on chrome safari and firefox, something about it being in the zip file caused the itch.io processor to fail. Thanks for the help all good now!