Do you use Ideal DVD Copy? If so, please eject the original DVD, then restart your computer, and close all the other applications and try the following steps to shrink the DVD again.
open our program and click the third "Configuration" button in the left bottom corner of the main window, click "Shrinking" tab, check "Prompt" and save it.(after finish compressing this DVD, you can restore this option to your favorite one.)
Copy the DVD to your hard drive without compression. Please choose 'To Hard disk...' from Destination dropdown list to select a folder on your hard drive as the target. And please click "No" when our program prompts you to compress the DVD or not.
Compress the DVD from hard drive. Please choose 'From hard disk...' from Source dropdown list to select the "VIDEO_TS" folder of the DVD as the source. And please click "Yes" when our program prompts you to compress the DVD or not.
Hope you could succeed. If still fail, please keep the original DVD into your drive as source and click the icon on the left top of the window of Ideal DVD Copy, then click "Export bup files" to export a .buz file and attach it to our support team email@example.com through email. We will help you.