object has no attribute 'data'

[cwlinghk]

I ran the Basic usage code on the top page and received the following:

File "C:\Users\admin\anaconda3\lib\site-packages\wsdiscovery\message.py", line 51, in parseSOAPMessage
return parseHelloMessage(dom)
File "C:\Users\admin\anaconda3\lib\site-packages\wsdiscovery\actions\hello.py", line 78, in parseHelloMessage
env.setEPR(dom.getElementsByTagNameNS(NS_ADDRESSING, "Address")[0].firstChild.data.strip())
AttributeError: 'NoneType' object has no attribute 'data'

Does anyone have any hints? Thanks a lot.