Thanks for your question. Are you, by any chance, using an Apple memory card reader to transfer these files? As these only recognise file structures that are compatible with Apple products, and therefore won’t work with non-apple products.
If not, and you are attempting the transfer another way, would you be able to give a bit more information regarding you how are trying to transfer these files so that i can help you better?
You need to download the Olfi App, or use a USB card reader that is not Apple branded, and that utilises an App so that the Apple device can read it (do not buy a plug and play – it won’t work)
Is it one of the new ones without the USB connection? If so, you will need a UBC-C to Mini USBcable and use your Olfi as the card reader.
Initial Advice: (i don’t know how you’re trying to transfer and what your Macbook capabilities are)
Try a different cable as the data transfer wire may not be working.
Try a non-branded iOS card reader that utilises an App (like i-flash device)