It says memory card error - card is locked But the memory card is not locked

Without knowing what the specific error is this is my best guess:

SOLUTION 1 - Unlock the memory card.
There is a Lock switch on the left side of the SD card. Make sure the Lock switch is slid up (unlock position). You will not be able to modify or delete the contents on the memory card if it is locked.

SOLUTION 2 - Toggle the lock switch.
If the lock switch is not on lock:
1. Slide the switch up and down. Repeat this 3 times.
2. Let it stay on the Lock position for 30 seconds.
3. Slide the switch up to unlock the card.
4. Try to transfer files into the device.

check you sd card there is lock and unlock switch. unlock that button

pull the card out

find the slide button on the side and slide it to the "unlock" position

put card back in

enjoi

Format memory card by using card reader, then try it.

Did you format the card in the camera before trying to use it?

SD cards have a slide switch along one edge. The position farthest from the contacts locks the card, protecting it from writes. The position nearest the contacts unlocks the card. If the switch is already in the proper position, slide it fully the other way and then back again.

Try reading the card independent of a camera i.e. on a computer or a photo kiosk to determine if the card is readable damaged

There is a little slide switch on the side of the memory card. Good luck!