Your comments

I have learned that it shows a failed upload, but if you wait for the upload screen to go away, then go into your projects, the upload was actually successful after a while. Then you can use the tool to repair your model. It just seems to be an issue with the user interface. Someone else pointed out that they just don’t show a successful upload if there is an upload queue. After some waiting, check your project list, then repair it from there. 

I just prepaid a year and had one successful upload. Now, all different file types and sizes stop at 90% on the upload. I agree that this is an amazing tool that I have been very impressed with in the past. I really hope that they can get this issue fixed!