I had a similar exception on buster with deluge-gtk 1.3.15-2: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/twisted/protocols/policies.py", line 120, in dataReceived self.wrappedProtocol.dataReceived(data) File "/usr/lib/python2.7/dist-packages/deluge/ui/client.py", line 179, in dataReceived d.callback(request[2]) File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 460, in callback self._startRunCallbacks(result) File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 568, in _startRunCallbacks self._runCallbacks() --- <exception caught here> --- File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 654, in _runCallbacks current.result = callback(current.result, *args, **kw) File "/usr/lib/python2.7/dist-packages/deluge/ui/gtkui/addtorrentdialog.py", line 197, in _on_config_values self.set_default_options() File "/usr/lib/python2.7/dist-packages/deluge/ui/gtkui/addtorrentdialog.py", line 496, in set_default_options self.core_config["move_completed_path"] exceptions.TypeError: Gtk.FileChooser.set_current_folder() argument 1 must be string, not None
I googled a two-years old link (https://stackoverflow.com/questions/44691151/ deluge-cant-open-torrents) where someone saying that the directories in Preferences -> Downloads must not be empty even if unmarked (I think the values for those directories are None by default after install). I did so and have no that exception now.