If you are using a Sandisk card with the adapter, try another adapter. Usually Sandisk is pretty reliable, but I got that message once, and using another adapter solved the problem.

Lots of good suggestions on here. Good luck!

Look at the SanDisk adaptor. There is a small sliding lever on the left side. If it is not all the way in the up position, then the disk is locked and you will receive an error code on the camera.

Format the card in the camera. Don’t format the card on your computer because it could be incompatible with your camera.

Would not allow me to format.

Thank you all for your help! I hesitate to say what I wanted to use this for, but your point is taken re the age of my equipment.

If you have a phone that takes pictures, the phone will most likely do much better than your old camera.

What brand of camera - what memory card ?