Most likely, your photo's file size is too large. Your photo can be no larger than 50k. You need to resize and possibly optimize your photo. You can do this using photo editing software on your computer. Refer to the help files in your individual software for instructions on resizing photos. Or, you can use our Photo Resizer. Once you've resized your photo and its file size is 50k or under, you can try to re-upload your photo provided there have been no bids on your auction. To do this, first log in. Go to your Members' area and then to the selling page.
You'll see the title of your auction listed under "Open Auctions". To the right of the auction title will be a link that says "edit" provided there are no bids on your auction yet. Simply click edit, and then re-upload the photo the same way you did when you originally started the auction.