I was editing a post with a primary intent to include pictures in the post that had been linked to by a low rep user. (The post appears to have been deleted). Normally this process is very easy - copy the URL, and paste it in the "From the Web" tab of the image uploader. However, it rejected this Dropbox image with the error message:
"Failed to upload image; the format is not supported"
I downloaded the pictures, which worked fine, but wasn't near as convenient.
This was the URL for one of the Dropbox pictures. https://www.dropbox.com/s/l4mqh9ji0p4sdu7/Screen%20Shot%202012-12-15%20at%2011.20.25%20PM.png
Is this happening because it is a secure HTTP request or is there a way to mitigate this problem in the future?