Vid-axzxp.mp4 -

Try using the default gallery or download the VLC for Android or VLC for Mobile on iOS which can play almost any MP4 encoding.

Look at the folder it is saved in. If it is in a folder like WhatsApp/Media/WhatsApp Video , check your recent chat history to see who sent it. VID-Axzxp.mp4

Could you tell me or what you expect it to contain so I can give you a more specific guide? Try using the default gallery or download the