Decided to reply here rather than start a new thread since I seem to be having the exact problem!
I upload the image, it seems fine, I see it in the preview, where it asks you to crop it, but when I click to upload the result is nada!
I've already clicked the support thing so just waiting to hear from them, I just thought I would ask if anyone else had this experience and if and how they fixed it. It's a long shot, but I already tried making the image small, different browsers, etc. I do have this other account (that I'm phasing out) and in there it still works.
I'll just wait for support to reply but I'm not holding my breath. I might go back to my old account but was really enjoying my new user name lol