MX Player will show a dialog: “Custom codec loaded successfully. Restart the app to take effect.” Force-close MX Player (swipe it away from recent apps) and reopen.

Tap that field to open the file selection explorer. Browse to your device's local folder path (typically located inside your native system Download directory) and pick the mx_armv8_neon.zip file. 4. Finalize Installation

Browse to your device’s default folder and select the downloaded zip file.