Hey guys. Since a few days ago, after updating firefox, suddenly all the top sites shortcuts which were on new tabs disappeared. and not only that. all new tabs I open, they are "Fully" blank. I can't even see the firefox icon at the top left, or the gear Icon on top right of the black pages. I refreshed firefox a few times and each time they came back but after a few minutes they disappeared again. at first I thought maybe adblockplus is causing the problem. but even after removing it, it happened again. Until I finally noticed this only happens whenever I refresh, and then try to change the position of the tiles, or edit them. the moment I touch the tiles and want to edit them or change their place, they disappear in new tabs. What should I do?

Any help will be appreciated.