Did you look at your history to see if they were still there.

Did you look at your history to see if they were still there.

Restoring previous session did not work (it said it encountered an issue, the list of tabs there was empty). There were no recently closed windows or tabs.

During such crashes the chances are very slim that anything was saved correctly to retrieve the information and if your "History" didn't show the sessions then the chances are they are gone as result of the crash.

During such crashes the chances are very slim that anything was saved correctly to retrieve the information and if your "History" didn't show the sessions then the chances are they are gone as result of the crash.

Yeah this is why my question is specifically about these two points: 1. I have shadow copies of the session from a week ago, these copies are corrupted, but not due to the crash. Is there a way to fix the corruption and somehow still decompress them and possibly retrieve a partial list? 2. Sync was always turned on. The moment I started Firefox and it was not able to restore the previous session, it overwrote the open tabs from this Computer. However, previously the open tabs were synced, so that must have been stored at some point in the database and it may be possible through some logs to retrieve the old state of this entry or to revert the last few transactions.

Crashes never guarantees anything was saved or saved to history that is what a system crash is by nature. This us why if you do alot of sessions one should bookmark them so if crashes do occur there is a bookmark start the sessions again. Sync syncs between devices it’s not for backup purpose.

Crashes never guarantees anything was saved or saved to history that is what a system crash is by nature. This us why if you do alot of sessions one should bookmark them so if crashes do occur there is a bookmark start the sessions again. Sync syncs between devices it’s not for backup purpose.

Sync saves to a database, which is kept both locally and on the cloud. Databases usually have a transaction history as well, to allow them to restore to a previous state.

Note that the files in the sessionstore-backups folder are LZ4 compressed, so you can't view them in a text editor.

You can look at this tool to inspect a compressed jsonlz4 sessionstore file. This tool works locally, no uploading is done.

• https://www.jeffersonscher.com/res/scrounger.html

Sync syncs between devices

It sync's with a Sync server

from for example https://support.mozilla.org/en-US/kb/how-reset-your-password-without-account-recovery-keys-access-data

Synced data When you sync your data with your Mozilla account, your data gets uploaded to Sync servers, based on your settings.

other articles that mentions Sync servers. https://support.mozilla.org/en-US/kb/how-stop-firefox-making-automatic-connections https://support.mozilla.org/en-US/kb/how-change-or-reset-your-mozilla-account-password https://support.mozilla.org/en-US/kb/how-firefox-sync-keeps-your-data-safe-even-if-tls-fails

markwarner22 said

Sync syncs between devices

It sync's with a Sync server

from for example https://support.mozilla.org/en-US/kb/how-reset-your-password-without-account-recovery-keys-access-data

Synced data When you sync your data with your Mozilla account, your data gets uploaded to Sync servers, based on your settings.

other articles that mentions Sync servers. https://support.mozilla.org/en-US/kb/how-stop-firefox-making-automatic-connections https://support.mozilla.org/en-US/kb/how-change-or-reset-your-mozilla-account-password https://support.mozilla.org/en-US/kb/how-firefox-sync-keeps-your-data-safe-even-if-tls-fails

Exactly, I found a local database as well in the profiles folder, called "synced-tabs.db". Sadly on my other computers it was instantly overwritten with the updated session, so no tabs shown there. However, that kind of database is indeed kept in the cloud, so my hope is that Mozilla may have an older version of it.

Note that the files in the sessionstore-backups folder are LZ4 compressed, so you can't view them in a text editor. You can look at this tool to inspect a compressed jsonlz4 sessionstore file. This tool works locally, no uploading is done.

• https://www.jeffersonscher.com/res/scrounger.html

I've tried that and other tools to decompress the files, unfortunately they are completely corrupted. I looked into them with a hex editor, but I very much doubt they are salvageable, there's a huge amount of zeros in there and even manually adding the magic header didn't help with decompressing it. Also unlike other lz4 files I've looked at in the hex editor, these ones are just translated into gibberish, so I think there is no hope to fix the corruption.