It does not answer your question, but for converting a DVD to an other video format, PD is, as an editor programm, the wrong tool.
Have a look at "Vidcoder". It's free and analyses the disc and can convert the main movie in e.g. a MP4 File. There are many more tools, as the always recommended "Handbrake". Unless you do not want to edit your DVD, they are all good tools for your purpose.
Hatti
Win 10 64, i7-4790k, 32GB Ram, 256 GB SSD, SATA 2TB, SATA 4TB, NVidia GTX1080 8GB, LG 34" 4K Wide, AOC 24" 1080