Just to clarify that a bit more:

What happens if you exit Firefox without shutting down Windows, and then start it up again? I'm assuming you have Firefox's startup option set to "Show my windows and tabs from last time" -- does Firefox load the tabs, or display the normal crash recovery screen, or display the blank crash recovery screen?

In case it is a factor here, do you use the session history features of Tab Mix Plus, or just Firefox's built-in features? (TMP's settings are shown on the help page here: http://tmp.garyr.net/support/viewpage.php?t=3&p=session-startexit)

By the way, when this happens, could you copy your session history files to a safe place for later analysis? Here's what I mean:

Try to rescue any sessionstore files in your currently active profile folder. You can open that folder using either

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help menu > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Show Folder" button. This should open a Windows Explorer window showing the files.

Copy all files with sessionstore at the beginning of the name to a safe location such as your Documents folder. These may include:

• sessionstore.js (current session)
• sessionstore.bak (previous session)
• sessionstore.bak-datetime (session from when you last updated)
• sessionstore-number.js (created when sessionstore.js is locked)

If Windows doesn't show all of the file extensions, you can turn off that hiding feature using the steps in this article: http://support.microsoft.com/kb/865219.

If needed, these threads describe various techniques to rescue the URLs from the sessionstore.js or sessionstore.bak file:

• Using Firefox's Browser Console (formerly known as Error Console): https://support.mozilla.org/questions/969046#answer-471950

• Using Firefox developer tool "Scratchpad": http://forums.mozillazine.org/viewtopic.php?f=38&t=622036&start=60&p=12098147#p12098147

• Using a third party website: https://firefox-session-restore.herokuapp.com/

Do any of those work on your file(s)?

It's much more a post laptop shutdown occurrence than merely closing FF.

I use FF's native session history. Is TMP's recommended over FF's? If so that's easy enough especially if it solves the problem. Been a FF user forever and had never really since this very much at all. All tabs would always appear. And session restore page would appear as well, not a blank tab like it is now, so it was just one click. It rarely ever happened until this pretty problematic 29.0 rollout.

I pin the tabs I want open always. But had been doing that too for a long time without problems.

No, I don't think anyone really recommends using TMP's feature. The Session Manager extension generally is considered the best way to manage extra session files (e.g., saving more past sessions, or saving outside of Firefox's profile folder). But I haven't used either of them myself.

And I don't know whether either of them would make a difference.

It's hard to think of what might be happening during Windows shutdown or startup that could empty your sessionstore.js file. Do you use any cleaning or privacy-enhancing utilities that could be zapping the file?

Yes, I use the utility System Mechanic from iolo technologies, but I've been using that for almost as long as FF. It does all kinds of clean up, registry work, hard disks errors, memory defrag, file realignment. It may be the culprit. But why after all these years?

System Mechanic or not, Chrome functions perfectly. I'm also going to start really using the Maxthon Cloud Browser which I downloaded a while ago, which has some amazing features.

FF 29.0 and above has been a UI disaster, as well as so many other problems for devoted users like me. I don't really understand how FF became the one trying to keep up and Chrome took over the uniform look, cross-platform browser leader position. At least work it out before competing in the space with radical UI changes and general bugginess.