DVD Shrink won't open DVD+R - says invalid navigation structure

Over the past 3 years, I’ve copied about 2/3 of my vhs film noir collection to dvd (about 150 films) using a variety of vcr-dvr combo units since it’s been my experience that these units are bascally junk and last only about 8 - 10 months if I’m lucky. But I digress, that’s not my problem.

I belong to several trading groups and have no problem copying any of these movies for other members if they were copied to dvd-r. However, any of the films that I put on dvd+r can’t be copied because DVD Shrink won’t recognize the format - I get the message “Invalid Navigation Structure” when I insert it into the disc drive. A lot of these films were not commercial films to begin with - they were taped off TV so size or protection weren’t a problem .

I’m new to this whole process. Does anyone have any suggestions as to how I can get into these dvd+rs and make copies of these movies? Thanks!

If these were recorded on someone’s DVD recorder, they could be in VR mode, which Shrink will not touch. What files are on them?