Does your Firefox crash a lot since you ask about this ?

PB mode means that no session data is stored in the profile folder and this means that when Firefox crashes there is no history or tabs that can be restored. If you experience a lot of crashes then be cautious and possibly bookmark important pages.

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

cor-el, thnks for responding.

I did have a crash as it happens, but I am not overly concerned about a one-off crash to be honest.

My query is about what happens to the private session data in this case.

For presumably Firefox keeps some running data while the private window is active, Even if it removes everything when the session ends?

But what happens to this temporary private session data when Firefox crashes?

Thanks.

In PB mode all session data is kept in memory, so it get lost when Firefox crashes just like happens when you close/exit Firefox normally when you use PB mode. When it comes to session data in PB mode there is no difference between a crash and a normal closing: you always lose you session data as it is purged automatically.