Some users have reported that Clippings has stopped working on Firefox 56. Affected users have observed that the Clippings toolbar button is unresponsive (it doesn't open Clippings Manager), and the Clippings submenu on the browser's context menu is missing.
If you are experiencing this problem, check that you have upgraded Clippings. Multi-process browser tabs is gradually being enabled to users in recent versions of
Firefox, and you need to have at least Clippings 5.1.2 in order for it to function with multi-process browser tabs.
Make sure you turn on automatic add-on updates in Add-ons Manager so that you don't miss any important updates. This is especially important for the upcoming release of Clippings 6, which will support Firefox 57 and newer. More information on Clippings 6, as well as a call for beta testers, is coming soon.
Reminder to Firefox users: Back up your clippings!
If you haven't backed up your clippings to prepare for the upgrade to Clippings 6, do it now! Read the Clippings 6 page on the AE Creations website to learn how to prepare for the upgrade to the WebExtension version of Clippings.
Users of Clippings 5.5.x should be seeing reminders to prepare for Clippings 6 in Clippings Manager, and in the "Get Ready for Clippings 6" menu item in the Clippings context menu in Firefox.