For the Windows version:
Click on the Load DVD button and then choose the correct source drive, and then choose the VIDEO_TS folder to load the disc. You will then get the following option as shown below to choose All Movies from the DVD.
Tip: To make All Movies the default setting click on Menu Preferences Convert and then set the DVD Load Mode to All Movies.
For Mac version:
Launch the product and click UniConverter (originally Wondershare Video Converter Ultimate) menu on the top, go to Preferences >> Convert tab >>Load Contents in a DVD and select All Titles from the drop-down list. Then load the DVD and try again.