Solution
The SD memory card, SDHC memory card, SDXC memory card or Eye-Fi cards have a write-protect tab.
If the ⋖Write Protect Tab⋗ is in the locked position, the following screen appears.
During shooting :
If [Memory card locked] appears in the upper portion of the screen, and [Recordable shots] or [Elapsed Time] shows [0]*, shooting is not possible.
* The above indications may not appear depending on the model of your camera.
During playback :
If you try to delete an image and [Memory card locked] appears in the lower portion of the screen, the image cannot be deleted.
If [Memory card locked] appears on the [LCD Monitor] of the camera, the ⋖Write Protect Tab⋗ of the memory card being used is in the locked (downside) position, so you cannot capture or delete images.
To unlock the tab, slide the ⋖Write Protect Tab⋗ of the memory card upward.