I right tried to upload an image to use in a post, but it was not accepted because the following error:
Failed to upload image; the format is not supported
The image was a JPEG; I also tried with a PNG image, but I got the same error. I then noticed the URL started with https://, tried with http:// but I got the same result.
The only way I had to add the picture was to take a screenshot of it, and then add it to the post.
Are there other restrictions that are applied? This is the first time I have such an error.
This is the image I am trying to include: http://drupal.org/files/project-images/path_breadcrumbs_settings_page.png.
I have tried with Firefox 21 and Safari 6.0.5 (8536.30.1) running on OS X 10.8.4, but the result doesn't change.