Go to the "playback" tab for playing back recordings.
Those are not "files" on your log, they are alarm events. It is telling you there was a movement detection event. But if the device is not configured to record on those events, there will be no video recording associated with it.
That is, the fact that there is a "motion detection" event on the log file does not mean that there will surely be a recording on that exact day/time.