Thanks for replies guys. And sorry for late response (vacations are required sometimes).
I did check everything you suggested and DVD is actual DVD: there is correct structure, it is playable in standalone DVD player and it is not protected. As far as I can remember, it was created with Pinnacle Studio 9 or 10 or 11. But whatever it is, it was created correctly.
I can say that because I was able to open it with DVDFab 9 !! I can make a copy of it, I can rip it into the AVI, MP4 but not the maximum of quality as MKV Passthrough. What I get out of 4.7 GB disc is less than 1GB file.
When I tried to rip MKV Passthrough I got "Error = config_mobile empty oformat helper mkv"
I did try to rip in VOB format and surprise, surprise... no issues (except I don't know what to do with it).
And, as I said, nothing is possible in DVDFab 10.