New
#1
New tab thumbnails don't show in Firefox
Firefox 15.0.1
When I open a new tab the thumbnails flash for a split second, but then disappear to leave a blank page. It worked previously, but I don't recall if I already had version 15 then.
I read that this may be caused by a full cache, so I cleared it, but even after visiting several sites after that nothing shows. Firefox is set to remember history.