For high-quality conversion or reducing file size, Handbrake is a standard choice. : Select the MKV file. Output : Choose MP4 from the Format menu.
If your file is named 06. Shor.mkv.mp4 , it might be an MKV file that was manually renamed or an MP4 file with a confusing name. 06. Shor.mkv.mp4
: Right-click the file and select Properties to see the "Type of file". For high-quality conversion or reducing file size, Handbrake