Hello Vlad92,

Maybe you could rename or remove these files in your Firefox profile folder (if present) with Firefox closed :

"logins.json" and "key4.db"

Go to the 3-bar menu (or press the Alt key) : Help => Troubleshooting Information => Profile Folder => Open Folder

Also see : http://kb.mozillazine.org/Profile_folder_-_Firefox

Hi McCoy, Thank you for your reply. I tried to remove those files, but as expected all the logins+passwords registered has gone. So I had to put those files back... Clearly Firefox password change cannot be done as the field accept only 20 digits. If no solution I'll stay with my 30 digits password.

re- install firefox, and try again.

Do you have both key3.db and key4.db files in the profile folder?

If that is the case then try to rename key3.db to key3OLD.db.

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 Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Hello Cor-El, I have no key3.db file, only key4.db. I don't want to lose all the registered passwords, so if Firefox can't make me change my password because the current one is too long, I'll stay with it. Thank you for your help anyway. Best regards

FFus3r said

re- install firefox, and try again.

Hello FFus3r, Will I lose all my registered passwords if I re-install Firefox?

Best regards

How long is the current master password?

Are there any non ASCII (e.g. accented or Unicode) character in the MP?

Vlad92 said

If no solution I'll stay with my 30 digits password.

If you don't want to rename/remove one of those files in your profile folder (and I totally understand why you're not eager to do that), sticking with your current password might be the best option.

Here's someone with a similar problem :

https://support.mozilla.org/en-US/questions/1225972

The fact that you use 30 characters can't be the problem : they were accepted when you first entered them and your MP has worked ever since .....

Maybe this article might interest you (for future reference, who knows .... ) :

https://en.wikipedia.org/wiki/Password_strength

Vlad92 said

FFus3r said

re- install firefox, and try again.

Hello FFus3r, Will I lose all my registered passwords if I re-install Firefox?

Best regards

NO,

see this page:

• https://support.mozilla.org/en-US/kb/uninstall-firefox-from-your-computer#w_remove-user-data-and-settings_2

You only see bullets in a password field, so you can't see if the 20 characters you see aren't scrolled.

Are you sure you typed the full and correct password?

If you aren't sure then try to use the clipboard with a copy and paste.

cor-el said

You only see bullets in a password field, so you can't see if the 20 characters you see aren't scrolled. Are you sure you typed the full and correct password? If you aren't sure then try to use the clipboard with a copy and paste.

Hello Cor-El, Right I only see bullet, this is why I used arrow keys to be sure that only 20 characters can be written or copy-past. Best regards

McCoy said

Vlad92 said

If no solution I'll stay with my 30 digits password.

If you don't want to rename/remove one of those files in your profile folder (and I totally understand why you're not eager to do that), sticking with your current password might be the best option.

Here's someone with a similar problem :

https://support.mozilla.org/en-US/questions/1225972

The fact that you use 30 characters can't be the problem : they were accepted when you first entered them and your MP has worked ever since .....

Maybe this article might interest you (for future reference, who knows .... ) :

https://en.wikipedia.org/wiki/Password_strength

Hi McCoy, I tried to remove those files as you know and put them back... 30 characters were accepted when I first entered them few monthes ago, right . As explained to Cor-El above when I copy-past 30 characters in the password field only 20 are written (I used a simple arrows keys test). I had a look on the link you sent: It seems I have the same issue.

Best regards

cor-el said

How long is the current master password? Are there any non ASCII (e.g. accented or Unicode) character in the MP?

Hi Cor-El, I have no non ASCII character in the master password. Best regards

I tried a long master password (36: a-z0-9) and was able to change the MP even though the password field only shows a maximum of 20 characters. Both typing and pasting works.

Does it work if you try to change the MP via the "Change Password" button under "Certificates > Security Devices"?

• Options/Preferences -> Privacy & Security
  Certificates: View Certificates -> Security Devices -> Software Security Device

cor-el said

I tried a long master password (36: a-z0-9) and was able to change the MP even though the password field only shows a maximum of 20 characters. Both typing and pasting works. Does it work if you try to change the MP via the "Change Password" button under "Certificates > Security Devices"?

• Options/Preferences -> Privacy & Security
  Certificates: View Certificates -> Security Devices -> Software Security Device

Hi Cor-El, Thank you very much for your help. Unfortunately I still cannot change the MP even in this area. You were able to change your long MP? I have no idea what could be the cause of my problem. Best regards