Backing-up Disney "Muppet Christmas"

Very new to all of this. Forums and creating back-ups. I’ve read a lot of great advice from members and tried using it - with success. Currently use nothing fancy, current versions of all (Ripit4Me/DVD Shrink/DVD Decrypter). My daughter wears out DVDs faster than any human being alive. I’ve tried two different copies of Muppet Christmas Carol, but they both stop “ripping” - at the beginning of the movie file, on each. I read from advice from others that mfg.DVDs are infalable, so should I try to find a third copy or am I missing something.