Regarding the stuttering problems some people have had with 4K77, I am reminded of an issue I had with NJVC’s 50GB bluray of Harmy’s SW DeEd on my standalone player. I noticed some weird stuttering in the video whereby it seemed to be losing a couple of frames each second, but the audio sounded fine.

I eventually discovered that by switching to an audio track other than the first (default) one, the video problems went away. It might be worth a try with the UHD 4K77 file, in case the underlying problem is actually with the software struggling to read the audio track at the expense of messing up the video.

(I realise this is a long shot!)

Bluto