Did you look here?

• Edit > Preferences > Advanced : Encryption: Certificates - Security Devices

Select the device that you want to remove and click Unload

It did not solve the problem. I get the answer: can't take away the module.

Rename secmod.db (secmod.db.old) in the Profile Folder in case there is a problem with the file.
You may have to rename cert8.db (cert8.db.old) as well.
Firefox will create new files.

The file cert8.db stores user certificates and intermediate certificates send by websites, so if you have certificates that you want to keep then you may want to export them now and import them after having removed cert8.db.

Can't find the file secmode.db or cert8.db. I've looked in the profile folder of Firefox and the rest of thr filesystem .

The profile folder(s) are in a hidden location ~/.mozilla in the home directory.

~/.mozilla/firefox/<profile>/

See:

• Help > Troubleshooting Information > Profile Directory: Open Containing Folder

Thank You!!

Thank you cor-el. It solved my problem!