Traceback (most recent call last):
  File "/usr/lib/x86_64-linux-gnu/pitivi/python/pitivi/undo/undo.py", line 281, in _getTopmostStack
    stack = self.stacks.pop(-1)
IndexError: pop from empty list

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/x86_64-linux-gnu/pitivi/python/pitivi/timeline/timeline.py", line 760, in __dragLeaveCb
    self.app.action_log.commit()
  File "/usr/lib/x86_64-linux-gnu/pitivi/python/pitivi/undo/undo.py", line 214, in commit
    stack = self._getTopmostStack(pop=True)
  File "/usr/lib/x86_64-linux-gnu/pitivi/python/pitivi/undo/undo.py", line 285, in _getTopmostStack
    raise UndoWrongStateError()
pitivi.undo.undo.UndoWrongStateError