Firefox se ne poveže, drugi brskalniki delujejo

Firefox won't connect to any website, but other browsers will.
Najdem kup rešitev, ki pa ne pomagajo.
https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can
https://support.mozilla.org/en-US/kb/fix-problems-connecting-websites-after-updating
https://support.mozilla.org/sl/questions/987145

Težava je bila v tem, da je tekel še en Firefox, viden le v tasklist:

tasklist /FI "IMAGENAME eq firefox.exe"

Image Name                     PID Session Name        Session#    Mem Usage
========================= ======== ================ =========== firefox.exe                  11760 Console                    1    406.680 K

Potem, ko task ubijem, Firefox deluje:

taskkill /F /FI "IMAGENAME eq firefox.exe"
SUCCESS: The process with PID 11760 has been terminated.