When you see the error, tapping the "Software Decoder" button (the little "SW" icon) sometimes fixes it. Understanding why is crucial:
The most common misconception is that the MX Player developers are lazy. They are not. The issue is , not technical. mx player codec missing
"I have tried to use my default set of tools (codecs) to decode this video stream, but I don't recognize the format, or my default tools are incompatible with your device's processor." When you see the error, tapping the "Software