I was using an M5 to video some speeches at a wedding a few weeks ago and after a few minutes the camera screen brought up an error message which I don't remember exactly, but I think it said something about having to restart. I turned the camera off and back on and I could video again and it worked fine after that for the rest of the evening. However, the file on the card that relates to the video when the error arose is a .DAT file and it's 1.53GB, which is about the same size as another MP4 file on the card for a video of about the same length. Does anyone know of a way to salvage video from a DAT file, or should I just accept that the video is lost.