In the camera settings there are two video formats available. One is MOV used on Macs (& PCs with appropriate video codec installed). The other choice is MP4 supported natively by most newer PCs. Check the file extension for the video. If it is MOV & you are attempting to playback on a PC, search for the MOV video codec (or just install QuickTime on the PC). If you are using a PC change the P3 camera setting to use MP4 for videos.