My MSI GT70 0nc-008us (w/i7-3610QM, GTX 670M/3GB GDDR5, 16GB RAM, ) suffered a critical crash upon connecting a new Seagate Backup Plus Slim Portable 2TB hdd. Lost Win 7 (64-bit) primary account. Recovered account, which appeared intact. Contacted GeekSquad tech support merely to "check & confirm" that OS was not damaged. Tech mistakenly, without any notice, executed a "tune-up," thus rendering Firefox (& other programs that I've optimized & customized over the past 2 years) effectively useless to me. For most of my applications, the history upon which I so greatly depended throughout the day, every day, was "wiped-out." As if that wasn't bad enough, for Firefox, the tech removed ALL addons, extensions, "history," themes, etc., leaving Firefox in the most basic configuration. Due to disabilities, I could not use it in any productive manner after what he did. Thankfully, I always keep backups of the profile (which I luckily made the prior afternoon) so, when I called GeekSquad back to advise of them of what the tech did, another tech assisted me to so correct. Unfortunately, I had no restore points due to... ["...it's a long story..."] ...by a Norton Live Ultimate Help Desk tech (to which service I was previously subscribing). So this GeekSquad tech, to whom I spoke over the phone while he so endeavored, & who was surprisingly very competent & knowledgeable, analyzed my system and said the history from all of my Microsoft, Adobe & other applications, could not be restored. However, he deleted the active Firefox (default) profile & replaced it with the backup. It then "appeared" to be as it was before the mishap. However, I then noticed too few tabs opened. So I replaced the session. The chosen session opened as usual, but took longer to be accessible, and there were then 2 popups asking if I wanted to let scripts continue. The popups referenced the "session" & something about "tab mix plus" with a ".js" extension. After selecting whether to continue or stop the scripts, another 2 scripts popped-up. Whether I opted to allow the script to continue or stop the script appeared to make no difference. Within a couple of min's most of my tabs disappeared. It took a while to figure out that they had been erroneously put into groups. A few groups had names of groups I used to use, though most were untitled. I stopped using groups months ago. Also, to the best of my recollection, the script alerts (popups) which happened infrequently while using v21, have not occurred since upgrading to v23; until now. Please note that I had almost 200 tabs opened, which had been put into 12 groups. I eventually tried dragging the tabs from each group into a single group, after which it "appeared to be stable." Though I then reduced the number of opened tabs to 110, & am no longer experiencing this issue; unless I reopen my previous 187 to 208 tab sessions. [I'm wondering if those sessions could themselves be the problem...possibly corrupt?] Unfortunately, I will need to open (& leave open) a total of from 140 to 210 tabs in my default session (used throughout the day, everyday). Firefox previously functioned well with 200 tabs open, with only one or 2 crashes every couple of weeks or so; & it always restarted & worked fine. If i can provide any additional information to assist you in providing a solution, please let me know. A Google search revealed that others have suffered from the described problem with groups, though I found no solution. It is my hope that you aware of, and have successfully solved, this glitch. Anxiously awaiting your reply. Thank you ever so much in advance! All the best to you & yours. pb.