The Tab Groups (also known as Panorama) feature will be removed from Firefox in version 45. Learn More
Tab Mix Plus, version 0.4.2.1 or newer, includes functionality to handle the removal of Tab Groups (Panorama) feature form Firefox 45 and will help you to save your groups so you can continue using them.What will happen to my existing Tab Groups?
When you update to Firefox 45, if your last session contained Tab Groups, Tab Mix Plus session manager will save a backup of your session. You can use it the same as you use all your other saved sessions. All your existing Tab Groups will be bookmarked automatically and stored in the Bookmarks folder. You will be able to access them by clicking the Bookmarks button in the toolbar.
New 'Bookmark Session' is available in The Session Manager context menu. All your windows groups and tabs form the session will be bookmarked to a Bookmarks folder under 'Tab Mix Plus Sessions' folder.