TypeError: 'NoneType' object is not iterable

[Van R. <van...@ho...>]

Stacktrace:

    Traceback (most recent call last):
      File "timelinelib\wxgui\dialogs\editevent\controller.pyc", line 80, in on_ok_clicked
      File "timelinelib\wxgui\dialogs\editevent\controller.pyc", line 86, in _create_or_update_event
      File "timelinelib\wxgui\dialogs\editevent\controller.pyc", line 156, in _get_and_verify_input
      File "timelinelib\wxgui\dialogs\editevent\controller.pyc", line 174, in _get_start_from_view
      File "timelinelib\wxgui\dialogs\editevent\view.pyc", line 226, in GetStart
      File "timelinelib\wxgui\components\gregoriandatetimepicker.pyc", line 60, in get_value
      File "timelinelib\wxgui\components\gregoriandatetimepicker.pyc", line 120, in get_value
      File "timelinelib\wxgui\components\gregoriantimepicker.pyc", line 39, in GetGregorianTime
      File "timelinelib\wxgui\components\gregoriantimepicker.pyc", line 79, in parts_to_gregorian_time
    TypeError: 'NoneType' object is not iterable

Environment:

    Timeline version: 1.9.0 (d89b8d1eceb5 2016-01-31)
    System version: Windows, THOR-PC, 8, 6.2.9200, AMD64, Intel64 Family 6 Model 26 Stepping 4, GenuineIntel
    Python version: 2.7.6 (default, Nov 10 2013, 19:24:18) [MSC v.1500 32 bit (Intel)]
    wxPython version: 2.8.12.1 (msw-unicode)
    Locale setting: English_United States 1252
    Locale sample date: 11/22/3333