Specifically, for some users, the upgrade to Firefox 7 made it appear as if their add-ons had disappeared.
In response, Mozilla paused new updates to Firefox on Wednesday while it worked to fix the issue, and it also released a workaround for Firefox users who have installed Firefox 7. On Thursday, it rolled out a new Firefox update that eliminates the problem.
Mozilla is now encouraging all Firefox users to upgrade to Firefox 7.0.1, which is available for from the Mozilla site.
Case of the Missing Add-Ons
"We've identified an issue in which some users may have one or more of their add-ons hidden after upgrading to the latest Firefox version, affecting both desktop and mobile," wrote Mozilla add-ons product manager Justin Scott in a on Wednesday.