If you have a file on the card, it's been formatted. In future videos. back off on the video quality. High quality video gets recorded at H.265 and many video players don't have the necessary CODEC installed to play the newer format. Depending on what player you are using to view your file, you may be able to download the required CODEC. I think there are also free converters that will make H.265 into H.264 that you should be able to view.