.iso created with AnyDVD and the "Keep Protection" box unchecked and mounted with Clone Drive always works fine for me.
My earlier release Potter blu-rays are ripped to .mkv and that worked.
The only thing I can think of is that I understand some Blu-ray drive do not allow ripping. Perhaps it is your drive. But if you have past success in ripping with that drive this in probably not the issue.
Anál nathrach, orth’ bháis’s bethad, do chél dénmha