CKAR crash upon tree collecting - or executing not sure

[wooloogooloo]

From terminal:
Traceback (most recent call last):
File "codeklavier.py", line 227, in
perform(configfile=config, prototype=play)
File "codeklavier.py", line 113, in perform
eval(prototype.main())
File "/Users/Anne/codeklavier/ckalculator/ckalculator.py", line 96, in main
ck_deltatime=ck_deltatime, articulation=articulation)
File "/Users/Anne/codeklavier/CodeKlavier/ckalculator_classes.py", line 573, in parse_midi
self.ar.toggleShapeNext(parallelTrees=True)
File "/Users/Anne/codeklavier/CodeKlavier/ar_classes.py", line 151, in toggleShapeNext
self._shapes[str(t)]['shape'] = new_shape
KeyError: '0'