So I have been trying to convert my Blu-Rays using a combination of MakeMKV and Handbrake, so I have been able to get the MKV and am able to play them, but once I do the handbrake, and it runs through fine, I get an error when I try to play the m4v file. It says "The document _____ could not be opened. The movie is not in a format the Quicktime Player understands." Any ideas of what might be going wrong? Thanks.