There are two reasons
1. The image was likely too large
2. the image format you uploaded is .PNG which is not supported by the site (this type of file is what creates the black box images)
When you upload an image and submit on an entry, the site is doing 2 things.
The first thing it is doing is running a timer.
The second thing it is doing is that it is copying the image from your browser to a temporary location on the server. Then it runs the image file through the process to transform the image into what the site will ultimately use. This means it opens the temp file, then performs the resize operation, then saves a new temp file (or replaces the existing), all while it sends the required info to the Edit Queue or the commands to create a new entry, whichever it is you are doing. If you are uploading 2 images, it does it twice, or maybe 3 if three. Unknown to me if it is synchronous for your request, or with others, or if there is an internal operation queue or pecking order...
BUT back on track. If the amount of time it takes to complete the tasks in the "second thing" takes longer than the timer is set to go for, then you will have things like:
- updates that never show up in the queue
- broken entries (the 0 or -- blank entries)
Remember that the largest image (in dimensions) that ends up on an entry is 200 px wide, so you can shrink an image down all the way to 200 px wide and it won't be distorted by the site. I do not know what the capable top end of image dimensions are but as I said I always try to shrink down to 800 px width at the most for the images I upload myself.
So for this, shrink the image dimension size down and export to JPG type instead of PNG.
I'll send it back up, then. Thanks!
EDIT: Resent.
Still not there. Upload it into your Gallery and I can see if there is something wrong with the image.
Had to size down to get to the gallery, so that's my guess, but I'll let you take a look.