This may be a known issue, please disregard if so. I've clicked on a few photos at MP just now. Usually, this would result in an in-screen popup with the photo enlarged. This still sort of happens, but in addition, the opacity increases, and I see the word "Loading..." overlaid at the top of the popup. The opacity does not go to 0 again, and I can't click on any links in the somewhat obscured photo page. I assume you will see this issue easily but I can provide more details if needed. I tried it on Chrome in Win 10 and Linux.