(e.g., Telegram download, email attachment?) What device are you trying to play it on?
Click , select Video - H.264 + MP3 (MP4) as the profile. Set the destination file and click Start [1].
Matroska Video, a flexible, open-standard video container format that can hold a high number of video, audio, picture, or subtitle tracks in one file [1].
If the file does not play, it may be corrupted or missing codecs. Try using VLC to play it, or check the file source.
To give you more specific advice on this file, could you tell me: