Yup... Three things, actually.
1) You're using a conversion program to try to un-encrypt a DVD. The files on the DVD can't be used 'til they're un-encrypted. Need a different program for that.
2) You're using a file oriented program to attempt a DVD, which is, in essence, a bunch of files. This also won't work.
3) You're using (or trying to use) a video format for which the converter program isn't set up to use.
To get around at least some of these issues, use DVDfab for the entire operation (almost). Potential problems with that method:
1) If the DVD you're trying to do is a recent release, DVDFab won't be able to handle it.
2) Once you get the DVD decrypted, you'll need some utility to take all those BR bits, and convert them down to STD. format (I believe - if anyone knows another way, feel free to step in).
P.S. When you say Video Converter, I'm translating that as VideoFab - Correct?