Customized Thunderbird/Enigmail settings are reset to default on restart
A user has reported that setting Enigmail to encrypt Headers/Subject doesn’t stick after restarting Thunderbird. I can confirm as well.
In ~/.thunderbird/profile.default/prefs.js extensions.enigmail.protectedHeaders is reset to 0 after restarting Thunderird.
This setting is available in Thunderbird, in Menu -> Enigmail - click “Display Expert Settings and Menus” -> Advanced -> “Encrypt subject bu default”.