Traceback (most recent call last):


 "D:/2.7/build/inst/lib/python3.5/site-packages/cura\CuraApplication.py", line 707, in event


 "D:/2.7/build/inst/lib/python3.5/site-packages/UM\Qt\QtApplication.py", line 261, in event


 "D:/2.7/build/inst/lib/python3.5/site-packages/UM\Event.py", line 189, in call


 "D:/2.7/build/inst/lib/python3.5/site-packages/UM\Signal.py", line 315, in __performEmit


 "D:/2.7/build/inst/lib/python3.5/site-packages/cura\Settings\ExtruderStack.py", line 94, in _onPropertiesChanged
AttributeError: 'NoneType' object has no attribute 'definition'

```Traceback (most recent call last):


 "prepare_data.py", line 211, in <module>

run_cmdline(sys.argv)


 "prepare_data.py", line 208, in run_cmdline

prepare(**vars(args))


 "prepare_data.py", line 156, in prepare

print(misc.bold("Preparing the {} dataset...".format(c.name)))
AttributeError: 'dict' object has no attribute 'name'
