Use a format like YYYY-MM-DD_Description.mp4 .
Are you having , or are you just trying to find out what's in it ?
Most modern OSs can play MP4s natively using Windows Media Player or QuickTime .
Upload it to a service like Google Drive or OneDrive to ensure it isn't lost if your local drive fails.
Sometimes renames files with long strings during the download process.
If the video was cut off (e.g., camera lost power), use tools like Fix.Video or Untrunc .
If you have the file but cannot open it, follow these steps: