Pinned tabs are stored in sessionstore.jsonlz4 alongside with other session data (open tabs), so if this file doesn't get created when Firefox is closed then you lose both.

Did you check whether you can restore the previous session in this case?

• https://support.mozilla.org/en-US/kb/restore-previous-session

Safest is probably to use "Restore Previous Session" as the startup setting if you experience a lot of crashes.

If you have submitted crash reports, please post the IDs of one or more recent crash reports that start with "bp-".

• bp-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

You can find the report ID of recent crash reports on the "Help -> More Troubleshooting Information" (about:support) page.

• click the "All Crash Reports" button on this page to open the about:crashes page and see all crash reports.

Alternatively you can open about:crashes via the location/address bar.

See also:

• https://support.mozilla.org/en-US/kb/mozillacrashreporter
• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-crashes-closing-or-quitting
• https://support.mozilla.org/en-US/kb/firefox-crashes-asking-support

The restore previous sessions post didn't help much the option "restore previous session" option don't appear when I go to history and I did check the "Restore Previous Session" option as the startup setting. I don't know where the sessionstore.jsonlz4 could be, but I'm using windows and my browser is not instaled on the C: so shouldn't be file permissions. I did say that the browser was crashing but is not a proper crash, what happens is the browser begins to open, appear the window as loading (like when the tab's titles are loading), then imediatly close and open again and there it is without the pinned or previous tabs, the crash reports are empty. A clue is, aways when I open a anonimous tab then close the non anonymous one, it happens, the previous tabs are gone even if I imediatly open the browser again, but without anonymous tabs it can happen sometimes.

A video for easier understanding https://youtu.be/ekvA44fz81o

I've already lost 2 answers when editing them, well again, in short, I said crashes but they are not proper crashes, when I open the browser sometimes while loading the tabs titles and content, the browser closes and opens again without any tabs. Another problem that I have is, when closing a non anonymous tab with a anonymous tab open, I aways lose any pinned or saved tabs, and my browser doesn't have the "restore previous session button" this youtube video shows exactly the anonimous bug. Also this is a youtube video showing this buggy form that made me lose 2 answers, so you can see that I am not crazy.

We're sorry to hear that your Firefox seems to be crashing when you open it. Please perform the following steps to give us a crash report ID that helps us find out more about the cause of the crash.

1. On the keyboard, press [Windows] The image "Windows key" does not exist. + [R]. This should bring up a Run window that contains a text field.
2. In that text field, type %APPDATA% and press Enter. An explorer window should open.
3. From that explorer window, double-click on the Mozilla folder, then double-click on Firefox and then on Crash reports. Double-click on submitted.
4. Now, you should see a list of files that contain reports. Go to View > Arrange Icons by > Modified to get the most recent files at the top of the window.
5. Open the most recent 5 files with a text editor and copy the IDs.
6. Paste each ID with bp- into the reply window on the forums.

Thanks in advance!

You can find more information and troubleshooting steps in the Troubleshoot Firefox crashes (closing or quitting unexpectedly) article.

There is no crash reports on the specified folder, as I said they are not proper crashes, the browser starts to load, closes then loads again without tabs. About the buggy behavior when private tabs are used that I showed on video, any advice or info about it?

Chosen solution

Pinned tabs are bound to a specific window, so make sure to Quit Firefox while this window is still open and do not simply close a window and leave Firefox running with the menu bar visible. You can check History -> Recently Closed Tabs/Windows to see whether that has the lost window.

Regards, Will

You can create a new profile as a quick test to see if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles

If the new profile works, you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

Chosen solution Pinned tabs are bound to a specific window, so make sure to Quit Firefox while this window is still open and do not simply close a window and leave Firefox running with the menu bar visible. You can check History -> Recently Closed Tabs/Windows to see whether that has the lost window. Regards, Will

Yes, bounding to a window is what I thought that it would do, but private windows don't save any data, so a check to differentiate them would be the way. Just prioritizing the last window, without checking if it is private, is not a smart move, it will aways clear the data when the last opened window is private. I hope that a browser like this doesn't have this problem, and this instance is just a coincidence. Chromium-based ones surely don't have, this type of basic problem, and it should not appear in projects as big as this one.

You can create a new profile as a quick test to see if your current profile is causing the problem. See "Creating a profile":

• https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles

If the new profile works, you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

I switched to a created profile and without even recovering the data, the problem still persists, it is only me that have this problem? Can't anyone repeat the same process and and in the same problem? If not I will reinstall and see if is a corrupted instalation, I never saw something like a corrupted browser installation, but maybe it helps.