Hello. I am running Thunderbird 38.2.0 with Lightning 4.0.2 preinstalled. I have a problem with one of my calendars (installed on a Synology Webdav environment). I basically used the wrong credentials when creating the calendar and now I am not allowed to retype the user pass combo (as I would normally during email account creation if there is a login problem). Below there are some details. I have created a new calendar using Create New Calendar -> On the Network. Clicked Next. Specified an IP (company intranet). Typed in a name for this calendar, chose color. Clicked Next. I then got a brief login page from my server where I typed the wrong credentials (user//pass). When I go to the Calendar view the particular calendar is grayed out and the Edit and Delete buttons are also grayed out. If I try to select it, click properties, Switch this calendar On, it becomes grayed out again in a fraction of a second. I have tried to unsubscribe from it, and recreate it a few times, with various names, but Thunderbird/Lightning detects the Calendar URL and apparently uses the bad credentials. Is there a way to flush these credentials out? My best bet would be in Thunderbird Options -> Advanced category -> General tab -> Config Editor. I see there some entries (string/boolean), including a type "user set" string for the particular server calendar URL. I do not however see user pass combo associated with it. Does Thunderbird save the user/pass combo for each calendar URL? Where? Can I flush it?