That may be caused by the "write protect" tab being set to the back of it's slot. Remove the card from the camera & you'll see the little tab on the side of the card near the terminal end, & see if you can slide it forward until it stops. It could also be that the tab has broken off or fallen out of the card (I've got 2 with that problem).
"A skill is developed through constant practice with a passion to improve, not bought."
