Duplicate in File pull-down menu doesn't work

I keep getting the following error when I try and duplicate an open file.

Please describe the EXACT steps you are following so I can duplicate the error.
Currently, I don’t understand what you are doing.

  • open model
  • select File > Duplicate

That is enough to pop up the message.

https://mcneel.myjetbrains.com/youtrack/issue/RH-48185

I changed the message thread title.

This should be fixed in the latest RhinoWIP. Please give it a try.