Did you copy key4.db as well because you need both logins.json and the matching key4.db with the encryption key ?

Yes I have copied key4.db I have tried to copy both files from original profile, where I can see sites names for logins I have lost. But still I see only couple of passwords saved in the new profile. In the original profile I see a corrupted file too. I tried with a recovery pwd tool but it is just able to recover only new saved logins. So seems old file containing all my logins history is corrupted. So trying to restore it in some way.

Are there logins with a hostname and username and password present in the logins.json file ? Do you see logins in the 'corrupt' file and is the file plain readable text or is the corrupted file actually corrupted ?

If the logins.json.corrupt file is readable, then you can copy this logins.json.corrupt file to the profile folder and rename the file to logins.json.

If I open logins.json file through notepad, I see address of sites, logins and passwords are encrypted. I have 2 'corrupt' files in the original profile, both empty.

Our developers have finished their investigation and an update for Firefox for iOS has been published. This is version number 121.1 and we strongly recommend that you update to this as soon as possible.

If you experienced data loss with the previous update we apologise for the inconvenience this may have caused.

You may be able to recover your logins through one of two ways:

1. Use an existing backup of your Firefox profile that you may have taken (see this support article) or,
2. Take a backup of your Firefox profile (this article will help). Keeping Firefox closed, find the file named logins-backup.json. Take a copy of it, rename it to logins.json replacing the existing file with the same name.

We apologise that this has happened. Work is being done internally to reduce the chances of this happening again but we appreciate that this does not make up for the disruption this has caused you.

Thanks, I upgraded Firefox for iOS to 121.1. About the recover ways: 1. I have no profile backup to restore 2. if I backup my profile now and I replace logins.json with logins-backup.json - how can backup version recover my logins if it is a backup of actual profile? Sorry to ask but I want to be sure.

By the way, in actual logins.json file I see new logins I have added in last days, and these are shown in password menù. I see also old logins that are not shown in Firefox password menu.

thanks for your support

You need to check logins-backup.json in a text editor or open the file in a Firefox tab to see if there are lost logins stored in the file (i.e. you see a hostname and username and password).

• https://firefox-source-docs.mozilla.org/devtools-user/json_viewer/

If you already made changes to the logins, then it is likely that its original content is lost.

In such a case, you can look at a utility to browse System Restore points to see if there is an older copy of logins-backup.json and logins.json and #key4.db (this file stores the encryption key).

• https://www.shadowexplorer.com/
• https://www.nirsoft.net/utils/shadow_copy_view.html

I can see through a text editor hostnames in the logins-backup.json - but I cannot see usernames and passwords. I created new logins and they are added at bottom of json file. These are visible also in pwd menù through firefox. Oldest are not visible. This happened first from my iOS device and then it happened the same on the PC. So probably version 121 on iOS device corrupted the logins DB and then it propagated to other device through sync. I was hoping to obtain the inverse situation, restore what visible on windows system on iOS too.

Logins that have "deleted":true and no login data (username and password are encrypted, but the hostname is readable) are lost and can't be restored replacing logins.json with logins-backup.json. Creating new logins may not be a good idea as that may make it impossible to recover the logins.

So if replace the file doesn’t recover and create new logins doesn’t fix the problem, what do you suggest next? Thanks

You should be able to create new logins, you only cannot recover deleted logins unless they are still present on another device or you have a backup.