I have the same problem!
I have uninstalled, re installed, and I still can’t see theme images, header or any uploaded images.
Just a blue box with a white question mark.
However, if you right-click, you can open the image in another window or tab…
Needless to say, I’ve uninstalled wordpress and lost everything.
I was installing it into an add-on domain, if that helps anyone help me come up with a solution.
Thanks
