Whem I try to open Thunderbird I get message it's already open and I must close that one first to open a new version of Thunderbird. Nothing is open however.
I am not able to open Thunderbird. I get message it's already running and must be closed first, but no other Thunderbird is open according to task master. I have uninstalled it and reinstalled it but always get same message that it's already running. I did search and cannot find anything under Thunderbird after uninstalling it.
It was working fine in Windows 8 until a week ago.