'''Firefox Extension "Tab Session Manager" will not open saved session tabs as a GROUP''' ----------------------- From session to session, Tab Session Manager (TSM) displays any tab I have left open when I shut down Firefox. The TSM display of tabs appears in a vertical column (left side of screen) provided by the Firefox extension, Tree Style Tabs. At any time, I have a total of perhaps 600 tabs distributed among four separate windows in TSM, with each window linked to the task bar at screen bottom, letting me choose which window to display, full-screen, Running Windows 7 64bit SP1, I have had no problems until now displaying any of the four windows, one at a time, in the left column of my screen. Yet, now, I lost one of the windows when starting a Firefox session, and only three windows appear. Trying to recover all of the windows, since I have no menu option other than to restore the entire four window backup, I have clicked on TSM's top menu to restore all four windows. TSM does respond to my single, left-click, but restores only one window of the original four. A right-click of the TSM menu at top right of my screen makes no reference to "restore all windows in selected backup" or "restore all windows in latest saved session". Essentially, TSM has maintained a perfect record of all TSM backups ever made, each showing date and time, but since TSM now will not restore all windows, my operations in Firefox are crippled. In past incidents when windows have been missing, I have successfully restored all windows of any backup (each backup a set of multiple windows) chosen. My "brute force" recourse is to restore the entire Windows 7 volume from a very recent image made in the imaging application Macrium Reflect, since all the TSM windows are so valuable to my work. But that does not resolve the TSM failure to restore all of the saved tab collections. Meantime, I have located the repository of TSM image collections, and have been able to make test backups of large numbers of tabs, and restore them properly and completely. The major problem that remains is restoring all of the tabs from multiple windows contained in the same backup, as I could before. I have tried to reach a TSM community discussion on a GitHub link, but am uncertain where to proceed next. * BTW-- to view the entire screen, which is too small to review in the Mozilla Forum popup viewer, open the .PNG image in MS Paint.