I just got this message from a member:
Similar problem. On an ipad, some 7 years old, not able to upgrade beyond 12.5.7, I experience a range of issues since Saturday (April 1st this is upgrade to 4.7.8). The same issue on a multiplicity of browsers (Firefox, Opera, Safari, some of these freshly installed). All these items worked fine on Friday on the same tablet and iOS:
Thumbnail images do not appear anymore as thumbnails but only as links.
Videos that worked fine till Friday cannot be viewed anymore.
Replying to a topic is not possible anymore (a very tiny non-selectable area appears where I would normally type a reply, but it doesn't trigger the keyboard interface)
Whenever I see a small down-pointing triangle that should allow a sub-menu (as in e.g. "page 1 of 22 ▼"), it does not activate any menu.
Together, this renders the site quite useless on that device.
As stated, up to Friday, all these features worked fine on the same device.