The default download manager in Firefox started showing a strange behavior today: any file I try to download (either in the default \download folder or in a folder chosen by me) is actually downloaded by the browser but the download status bar of the file always shows an "unknown remaining time" message while being fully green (https://www.dropbox.com/s/n891ya38ifm83c3/Cattura%20di%20schermata%20%284%29.png?dl=0). The real problem is when I download files like .torrent that as soon as are downloaded need the torrent client to start (torrent client that doesn't start because for firefox the .torrent download is never completed). I tried disabling the antivirus (bitdefender) but the problem persisted. In Chrome downloads work fine (also with antivirus enabled).