Bob, that's interesting. Is what you're describing specific to BRAVE or Blurays in general and how they have been authored. I've had the dropouts on a wide-variety of blurays. From Thor to the Muppets movie to rental disks too (if I recall). Never happens at the same time stamp and always well into the movie... 45 min to 1 hour plus.
What I was describing was specific to the newly released Blu-ray for "Brave".
The point is, problems like this can also be disc problems or player problems. For rental discs, the problems can simply be due to damaged or dirty discs.
As usual, if you are experiencing frequent dropouts, you should investigate whether HDMI cabling is the cause. Start by trying a reduced bandwidth signal -- e.g., 1080i. If that works but 1080p does not then that's a pretty good sign marginal cabling is involved.