I suggest you use the config editor

Just tried but doestn make it work inserting this chain as new bolean:

lockPref("pref.privacy.disable_button.view_passwords",true)

Any advice?

The preference name is pref.privacy.disable_button.view_passwords

its value is True.

You started out with using the preference and then imported this lockpref statement that has no place anywhere but in a network managers tool box really.

Lockpref is used to prevent users from changing the preference from within Thunderbird and only works if you have sufficient network control to make the file it contains read only to the user. If a user can edit the file they can change it therefore making the supposedly locked preference completely open to the user to change. Just rename the file that has the preference. There are instructions here http://kb.mozillazine.org/Locking_preferences

Without the config file the locking does not work.

I always find it hugely amusing to see people trying to block access to their own data in this sort of manner. Your operating system provides screen locking and user account passwords. But instead of using them as intended you are looking for some way to stop the program making your life easier because of either ignorance or a misplaced belief that locking your screen is time consuming.

It is more than 30 years since my employer made it abundantly clear I was responsible for everything that occurred on my computer. either lock the screen when I was not in front of it or go to gaol if my credentials were inappropriately used. I quickly learned to use a password locked screen saver and to use windows hot spots to invoke it.

Thank you for the comment and your answer, I follow this steps: 1.- I create user.js on the profile directory. 2.- Create local-settings on the thunderbird /default/prefs/ with this lines: pref("general.config.obscure_value", 0); pref("general.config.filename", "mozilla.cfg"); 3.- I create a mozilla.cfg at the same path of the local-settings with this lines: // lockPref("pref.privacy.disable_button.view_passwords",true);

But when I load thunderbird it show that it failed to read configuration file, any other advice?

The solution was the files path:

thunderbird installed folder/default/pref/local-settings.js

thunderbird installed folder/mozilla.cfg

And thats all, works like a charm...