Security software is causing Firefox users to lose saved passwords

Firefox users are reporting that their saved passwords have been lost, with the problem seemingly caused by antivirus software rather than being an issue with Firefox itself.

Antivirus software such as Avast and AVG appears to be corrupting the file in which Firefox stores passwords, rendering it unreadable. Thankfully, passwords can be recovered, but -- for the time being --- they will be corrupted again when you restart your computer.

See also:

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• Mozilla promises to delete private data collected by Firefox fix and apologizes for add-on outage
• Mozilla issues new Firefox update to fix add-ons problems and warns users not to try dubious workarounds

At the moment, there have been no statements from any of the companies involved to explain what is happening, or what is being done about it. But, as reported by Ghacks, security software seems to be corrupting the logins.json that Firefox uses to store profile data including passwords. Luckily there are backups that you can use to -- at least temporarily -- get your passwords back.

1. Launch Firefox and head to about:support
2. Click the Open Folder link and then click Firefox
3. Look for a file called logins.json.corrupt and rename it to logins.json
4. When you restart Firefox, your passwords should be available again

Ghacks also suggests that you could try excluding the logins.json file, or the Firefox profile folder from security scans.

Another option is to roll Firefox back to version 67.0.1, but in the longer term you'll need to wait for an update for your security software to stop it from happening.