The video uses a very rare codec (e.g., AV1 or VP8 with odd parameters). Solution: The 1.49.0 codec does not support AV1. Use software decoding or a newer version of MX Player for such files.
MX Player 1.49.0 Armv8 Neon Codec a custom add-on designed to restore support for audio formats like EAC3, DTS, and AC3 Mx Player 1.49.0 Armv8 Neon Codec Zip File