Hi there.. When an sd card begins to fail, it may be readable in the pc, but not in the camera, or in the camera but not in the pc. Please transfer all photos to your computer, then format the card using the camera, not the pc. Take a test picture and then look at the card using the oc. Copy the photos from your computer back to the same folder that the test picture is in. This should resolve the issue. If this should happen again any time soon, it is an indication that the card should be replaced. Please give this a try and let me know how it works out for you. If you have any questions about how to do any of this, please let me know.
You're very welcome. If the information that I have provided has been helpful, would you mind taking a moment to rate my service? I'd really appreciate it! You can give your rating by selecting the stars located on the top right of the question page. Rating me does not close the question. It will remain open for followup questions and for further troubleshooting if needed. Thanks!