The skinChop command appears to be broken in the latest release for 2016.5.
We used to call it with an argument like this:
if not cmds.pluginInfo("SOuP.so", query=True, loaded=True):__main__.skinChop_SOuP().skinChop("pPlane1")
This now raises an error:
# Exception: Keyword argument "base" should be of type string or unicode. #
The argument is a string, so I am uncertain as to why this being raised.
I tried it based on selection and it did not raise the error but it resulted in only Transforms being created (no shapes).