Thank you kindly for the reply. Have visited MKV many times and learned much. I do understand what you say about 4K.
However, ever since I started ripping normal blue ray this problem has been around. In frustration I got in the habit of power off and on again to get reliable operation. Altogether there are 11 optical drives here. Four of them are the small self powered over USB and the only choice is unplug the drive and plug again. When that is complete the program starts working again, as if magic.
One of my desk top type drives was supplied as 4K UHD type HT-DL-St-BD-RE WH16NS60 from LG). It would not work at all. Fromm the MKV site I got there firmware file and installed. Now the drive does work. So at least I have a working drive
To be honest, if I was only doing a few disc's this not much problem. 2500 different story.
One other question maybe you could answer for me. I tried to search and got no results. What is the purpose of JRSidecar?? Is it information only or some operational purpose. Right now it appears it makes no difference if it is there or not.
It does supply one useful thing for me. After ripping a movie, any ripped file that does not have the JRSidecar, this tends to indicate the ripping failed.
Harroun