It seems you have access to the images, though they are definitely unreadable. I'm gonna "guess" that you've edited the images so that they are no longer readable. What image format are you using? I'm looking right now at various default images that ship with the professional theme and they all seem to be ok, with the exception of your gl topic icon and the header logo. even the header background image is returning errors.
so, my guess, edited and so unreadable images or unsupported image formats.
hope that helps