www.makemkv.com

Hi,
I want to convert the HBO series "The Pacific" from Bluray Disc.
Using the newest MakeMKV version 1.8.10 gives me an MKV file
with artifacts looking like a red colour grid.

Does anybody has a clue who to prevent this ?

I need some scenes from "The Pacific" in HD for an own movie project.

Are you sure that makemkv is to blame here? If you're able to play the video stream, and it's assembled in the right order, it's unlikely makemkv is at fault since it just losslessly copies the video stream into the mkv container. It sounds more like a graphics driver/video output/player bug. I seem to remember seeing VLC exhibit this sort of misbehaviour with either ATI or Nvidia graphics (sorry I don't remember which) on Windows. Have you reproduced the problem using other video players like mpv or MPC-HC? You might also try changing the video output method of a given player as all three mentioned offer different options you could try.