If your Image doesn't work, there are 3 things you can do:
1) Change the image size (Crop)
I just use either photobucket or Paint
2) Change the Image format thingy
I just use Paint for that. Copy the picture, save as, then make sure you save it as .jpg or .jpng.
3) Choose a new picture
If you do steps 1 and 2 and it still won't work, just get another picture
Hope this helps.