If the internal decoder fails, the most stable way to get Xvid working on Windows 10 in 2021 is to install a codec pack that integrates with your system. The is the industry standard. Once installed, MX Player (and other players) will automatically detect the Xvid codec.
Older codec packs often carry security risks. Here is how to stay safe: Xvid Video Codec For Mx Player 2021 Windows 10
If you have downloaded a modern version of MX Player for PC, it often comes with built-in software decoders that can handle Xvid files natively. However, if you are using a specific custom build or an older version of the player, or if the file was encoded using non-standard settings, you might encounter errors. If the internal decoder fails, the most stable