Test the DVD on the computer. If it plays properly, launch the software and click “Video Converter Ultimate” on the top bar menu and go to “Preferences”. Under the Convert tab, go to Load Contents in a DVD and select All Titles from the dropdown list. Then load the DVD and try again.
If the instruction above does not work, try testing more DVDs to narrow down the cause of the error. It can be a certain DVD with a special protection codec in it or if the error occurs on all your DVDs.
In this case, please contact us with the information of the DVD such as title, region code, purchasing link from Amazon (if applicable) for us to test.