One pic is worth a thousand words, so ...
The center of the screen is missing on all the video files. I also tried it with MC18, which is where I first noticed the problem. The files play back fine in VLC Media Player. Interestingly enough, the files also play back properly in MC17 - glad I kept a copy! In all cases, I use Red October (standard). MC18/MC19 has acceleration and VideoClock checked on. MC17 does not. Unchecking these options in MC18/19 doesn't fix it.
Not sure if this will help, but here's a screen print of the menu setup in MC17 ...
And now for MC 19 ... I played around with these and nothing seemed to make a difference ...
The green line on the right side of the screen doesn't show in MC17 either - I imagine that's about the thickness of the missing information in the center of the screen?
Hep me! Hep me please!!
PS ... The second screen grab also had the green line until I told MC to crop the edges 3% ... This problem is with ALL movies. My entire library is stored in MKV format, ripped from old SD dvd-r's.