I just pushed a fix for this issue:
It’s a hacky solution but it gets the job done. So, if you sync with the github, the THERM workflow should now run without issues in Rhino 6.
When I re-write the THERM workflow for HB+, I’ll have to make sure that I am not as dependent on Rhinocommon.
Thanks for finding and reporting this issue @JonathanStory !