Crash in carving preprocessing

[cstraehl]

  File "/home/cstraehl/Projects/PHD/code/src/lazyflow/lazyflow/request/request.py", line 218, in _execute
    self._result = self.fn()
  File "/home/cstraehl/Projects/PHD/code/src/lazyflow/lazyflow/graph.py", line 811, in __call__
    result_op = self.operator.execute(self.slot, (), self.roi, destination)
  File "/home/cstraehl/Projects/PHD/code/src/ilastik/ilastik/workflows/carving/opPreprocessing.py", line 181, in execute
    self.enableDownstream(True)
  File "/home/cstraehl/Projects/PHD/code/src/ilastik/ilastik/workflows/carving/opPreprocessing.py", line 97, in enableDownstream
    self.applet.enableDownstream(ed)
  File "/home/cstraehl/Projects/PHD/code/src/ilastik/ilastik/workflows/carving/preprocessingApplet.py", line 35, in enableDownstream
    self.guiControlSignal.emit(ControlCommand.Pop)
  File "/home/cstraehl/Projects/PHD/code/src/ilastik/ilastik/utility/simpleSignal.py", line 21, in emit
    f(*args, **kwargs)
  File "/home/cstraehl/Projects/PHD/code/src/ilastik/ilastik/utility/bind.py", line 29, in __call__
    self.f(*(self.bound_args + args[0:self.numUnboundArgs]))
  File "/home/cstraehl/Projects/PHD/code/src/ilastik/ilastik/shell/gui/ilastikShell.py", line 761, in handleAppletGuiControlSignal
    command = self._controlCmds[applet_index].pop()
IndexError: pop from empty list