cd'd to an external harddrive, started ranger and immediately hit / to search, then got this:

$ ranger
ranger version: 1.6.1, executed with python 2.7.9
Locale: en_US.UTF-8
Current file: None
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/ranger/core/main.py", line 134, in main
    fm.loop()
  File "/usr/lib/python2.7/dist-packages/ranger/core/fm.py", line 314, in loop
    ui.handle_input()
  File "/usr/lib/python2.7/dist-packages/ranger/gui/ui.py", line 208, in handle_input
    self.handle_key(key)
  File "/usr/lib/python2.7/dist-packages/ranger/gui/ui.py", line 142, in handle_key
    elif not DisplayableContainer.press(self, key):
  File "/usr/lib/python2.7/dist-packages/ranger/gui/displayable.py", line 261, in press
    focused_obj.press(key)
  File "/usr/lib/python2.7/dist-packages/ranger/gui/widgets/console.py", line 173, in press
    self.type_key(key)
  File "/usr/lib/python2.7/dist-packages/ranger/gui/widgets/console.py", line 202, in type_key
    self.on_line_change()
  File "/usr/lib/python2.7/dist-packages/ranger/gui/widgets/console.py", line 418, in on_line_change
    if cmd and cmd.quick():
  File "/usr/lib/python2.7/dist-packages/ranger/api/commands.py", line 380, in quick
    return self._make_cmd().quick()
  File "/usr/lib/python2.7/dist-packages/ranger/config/commands.py", line 1052, in quick
    if self._count(move=asyoutype) == 1 and self.AUTO_OPEN in self.flags:
  File "/usr/lib/python2.7/dist-packages/ranger/config/commands.py", line 1117, in _count
    deq = deque(cwd.files)
TypeError: 'NoneType' object is not iterable

(Tried to replicate it w/o success though.)