Dvd to generic - dvdfab stopped working



hello, im new here on the forum.
i have a question, im trying to backup a couple of movies on to my laptop, i’m running the double pass (it takes like 6 hours) but just before it should stop a window pops up and says “dvdfab console has stopped working, would u like to close” why is that. whats going on? so i close it out, pop out the dvd, and tried to play it. it worked, just dont know why it does that. instead of just shutting down correctly.

im running vista
pretty sure i followed all the instructions

please help

thank you