Data Exchange Keeps Failing

I have a VWX file & Lightwright file linked via the XML file for data exchange, but as I make edits in LW, I get an alert "Cannot create Dudley's LP v2017.xml Data Exchange has been turned off"  This happens even if I start a new LW file with the same data.  I'm almost at the point where I can turn data exchange off, but ... it is a rather large inconvenience.  

This was a VWX file that started in v2016 and was updated to v2017 after the scenic updates started getting pushed to me in v2017.

I'm also crossposting this in the Vectorworks forum to see if anyone bites there.

Thanks,
Simon