If you tell me what you need to do with the video (e.g., , recover it because it's missing, send it to a computer, or convert it to a different format), I can give you more specific steps.

Transfer the file to a PC/Mac and use a media player like VLC Media Player or the default Windows/QuickTime player. 3. How to Fix "File Not Found" or "Cannot Open"

You can share this .mp4 file directly from your media app to other applications (Email, Drive, Telegram, etc.).

Usually located in WhatsApp > Media > WhatsApp Video or WhatsApp > Media > WhatsApp Video > Sent [2].

Upload it to Google Photos or iCloud to free up space on your phone [3].

If this is a thumbnail or placeholder, ask the sender to re-send the video via WhatsApp to ensure a complete download.

Ensure the file has not been renamed or moved from its original folder.

Open the WhatsApp chat where the video was sent, tap the contact/group name, then check "Media, Links, and Docs".