If you already have this file on your device and it won't play:

Files with _source in the name are sometimes partial or require a specific media player to handle the Reddit DASH stream format.

Because this is a unique ID for a single piece of user-generated content, there is no general "guide" for it. However, if you are looking to access or manage this specific file, here is how you can proceed: Finding the Video

If you have the URL of the Reddit post containing this video and want to save it:

Use VLC Media Player , which can decode almost any .mp4 file, even if the metadata is slightly corrupted.

Use a site like RapidSave or Viddit.red .

You can search Google or Reddit directly for the string 0h035mcdgfe18quyrq954 to find the original thread where this video was discussed. Downloading the File