I am experiencing the exact symptoms described in this post.
When I try to create a badge for this place, I receive the error message:
Upload failed. Make sure what you're uploading is an image.
I have tried from both the website and from Game Explorer in Roblox Studio.
I have tried several different images, image resolutions, image content, image formats, as well as different titles and descriptions in case moderation was to blame.
When I tried creating a Badge for one of my own places, it created the badge with no trouble.
Edit: I somehow completely missed this post. Same issue, I believe.