Thanks for responding.
I am pointing to the .py and not the .bat file. The problem seems to be that there is the expectation that the python.exe file is located under the thirdparty folder (which it is not).
I have a version of python installed on my machine that I would like to use, but this is not in the pre-defined path that the script is checking, and subsequently I get this error:
Could not find thirdparty/win-python3.5-x64/python.exe!