Still having the 3mf upload error

tried contacting @MakerWorld_Beta with no success, ticket has had no response. Has anyone managed to get any information from them?

I have seen people being able to use save as, as a workaround but that doesnt work for me,
also tried using older versions of the program but that had the same result .
Im surprised I cant find any official posts around it , anyone has had any luck getting it working advice would be welcome