Please update to the latest version of DVDFab 22.214.171.124 at http://www.dvdfab.cn/download.htm.
If you still get some error message, please decribe the error message in detail.
When backing up your DVD movie with DVDFab 126.96.36.199, please click the Menu button (the down triangle) on the right top corner of the DVDFab screen, then click Common Settings, and choose General->DVD, click on "Pathplayer", disable it to copy your DVD movie again.
Please remember to turn it back to "Always Enabled" when done.
As a note: Pathplayer shall be on "Always Enable" mode for most of the dvd copying, only when you have problem copying a certain dvd movie, you need to change it to "Disable" mode. Please remember to change it back to Enable after finishing the copying.
BTW,could you mind to tell me what DVD did you backup?