Movies not playing properly after changing out a movie series

I am still trying to learn Kodi when I have time.  I have been trying to learn audio and have been playing with Kodi and Windows settings to get the best sound out of the hardware I currently have. So, I have been replacing movie files that I think have better sound to match what I have available in my home.  I changed out a movie series that I currently have that happens to be .mp4 format to .mkv and it wouldn’t play.  I followed the directions on creating a log so that I could see what I did wrong or if it was just the files.  The files that I changed to and wouldn’t play, play fine in windows media player.  I also swapped the movie files back to the original ones and that seemed to fix the issue. I am looking at the log and trying to find where it played the mkv file but can only find where I think it is saying I removed them from the library. So, I guess I am curious if the log will point me in the right direction if I can get some help.  Any help would be appreciated. Here is the log file for creating the movie play issue. Kodi.log