High capacity SD cards are so cheap now, it's easy to think they're all the same. However, if you're getting quirky results from your GoPro, consider your memory card. Not all cards are created equal when using high performance, quick writing devices, and it pays to check the official GoPro page for their list of recommended cards before making a purchase.
Also, be aware of buying SD cards through online marketplaces (as opposed to resellers) as the counterfeit SD card market is rampant.
Common errors when using an unsupported card include: shutting down during recording, "SD ERROR" on LCD screen, corrupted card, unusual abberations on your recorded footage, card not being recognised. Sometimes you can fix these errors by formatting the card in the camera, or you can try formatting the card on your PC. But if these don't work you may have an incompatible (or at least, sub-optimal) card.
This is our weekly series of technical tips to help you get the most out of your underwater gear.