Description of problem:
Added a torrent to deluge and shortly after this traceback popped up. 

Version-Release number of selected component:
deluge-gtk-1.3.13-1.fc25

Additional info:
reporter:       libreport-2.8.0
cmdline:        deluge-gtk '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' ''
executable:     /usr/bin/deluge-gtk
kernel:         4.8.6-300.fc25.x86_64
pkg_fingerprint: 4089 D8F2 FDB1 9C98
pkg_vendor:     Fedora Project
runlevel:       N 5
type:           Python
uid:            1000

Truncated backtrace:
torrentview.py:180:str_nocase_sort:AttributeError: 'NoneType' object has no attribute 'lower'

Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/deluge/ui/gtkui/listview.py", line 261, in stabilized
    result = sort_func(model, iter1, iter2, data)
  File "/usr/lib/python2.7/site-packages/deluge/ui/gtkui/torrentview.py", line 180, in str_nocase_sort
    v2 = model[iter2][data].lower()
AttributeError: 'NoneType' object has no attribute 'lower'

Local variables in innermost frame:
v1: 'mr.robot.s02e09.ep2.7_init_5.fve.720p.web-dl.dd5.1.h.264-ntb.mkv'
iter1: <GtkTreeIter at 0x558e34b86040>
data: 5
model: <gtk.TreeModelFilter object at 0x7ff10097a050 (GtkTreeModelFilter at 0x558e34b585e0)>
iter2: <GtkTreeIter at 0x558e34ac3eb0>