Robert's shapefile widget and M and Z values

I'm using Robert Sheitlin's excellent shapefile widget (Version 3.4) to allow users to import shapefiles into their map. Today one of our users received a shapefile from a client and it would not import. I investigated the issue and found that the shapefile had both M and Z values enabled. I suspected this might be the problem, so I used ArcToolbox (Copy Features) to make a copy of the shapefile without M and Z values. This new copy then successfully imported into the map using Robert's shapefile widget.

I just thought I'd share this tip, in case anyone else experiences the same issue.

Scott