Roku 3 4200X I put in a microsd card, power up, the screen MicroSD detected select to format appears for about 1 second then defaults to cancel and disappears. I don't have a chance to select Format. How can I format the microsd card?
Try waiting for it to completely power up before you insert the card. If that doesn't work then I'd say sometimes the hassle just isn't worth it for something that's not really necessary.
That worked. Thank you.