You may get "moov atom not found" error while trying to convert video files in our system.
moov atom is the special part of the file, which defines the timescale, duration, display characteristics of the video, as well as subatoms containing information for each track in the video. This atom may be located at the end of the file, which is why you may get the error when the file was not completely uploaded.
moov atom is essential for video decoding and without it, the uploaded video is unplayable, so it cannot be converted. We try our best to make the conversion even in the most hopeless cases, but if the file is not readable at all (like missing header or moov atom in video file) - there is nothing we can do at all.
So, if you see this error - either your files is corrupted or not uploaded completely.
We may recommend you to upload your files to Google Drive or Dropbox and choose them from these cloud services - this will lead to fast upload, fast conversion and this will ensure that files are uploaded completely.