: If you cannot play them, you can easily convert them to a more common format like MP4 using online tools like CloudConvert or Restream . Why the Notification (41)? The number in parentheses usually signifies a batch action :

: If you were working on these files, Dropbox might be notifying you of 41 recent changes or "conflicted copies". Troubleshooting

: A colleague or automated system may have just synced a folder containing 41 video segments.

: You likely have 41 new video clips or segments (often used in professional video editing or streaming) saved to your account.