Don't use external software to do cleanup in Firefox. There are a lot of builtin ways to cleanup data via "Clear Recent History" or via "Clear history when Firefox closes", so there shouldn't be a need to use external software especially if you experience dataloss. Either exclude Firefox from System Mechanic or check its settings or contact their support.

See also:

• https://support.mozilla.org/en-US/kb/delete-browsing-search-download-history-firefox

I have been using System Mechanic for over ten years with no problems. Based on what I read this was or is known problem for other users. System Mechanic treats the stored pass words as "junk" and erases them. It would be so simple if I know what the name of this file and protect it from being erased during this process.

logns.json and key4.db in the Firefox Profile folder are the 2 files that Firefox uses to store logins / passwords.

Perhaps Iolo System Mechanic hasn't kept up the changes made to Firefox recently with regards to the "new" / changed file names for files that are stored in the Profile folder; IOW, Iolo System Mechanic needs to fix their "stuff".

In the end cor-el is right, best not to use external applications to "clean Firefox'; use what is built into Firefox instead.

I do not use Firefox to clean my files. I use IOLO System Mechanic as a virus protection. System Mechanic had a lot of security features not in Firefox. For years the two programs worked in Harmony with each other. Somewhere System Mechanic thinks the Firefox password file is a security issue or just junk file.

Did you contact System Mechanic support and ask them about this issue ?

Yes, there answer was quite simple the problem is Firefox! I have been trying to resolve this issue for months. If I could only make a copy of the Firefox file where the passwords reside I could always reload the file after System Mechanic has erased it. What is the name of the file I need to save? So simple, but no one knows the name of the file?

The names of the password related files have been posted further up in this thread. For the passwords you need two files. The logins.json file stores the encrypted usernames and passwords you have saved for websites. The key4.db file stores the encryption key required to be able to decrypt username and password data stored in logins.json (previously key3.db was used). Those two files need to match to make this work, so you always need to backup and restore both files in the profile folder with Firefox closed.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Folder/Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder

See also:

• https://support.mozilla.org/en-US/kb/Profiles