Since the marshmallow update yesterday I have been unable to write or remove anything from my SD Card. All of the media files (pictures and music) are still there and retrievable but none can be moved or erased through the phone or when hooked up to the computer. I am unable to add a backup file or format the card with the phone. I have factory reset and the problem persists. Has anyone had this issue and found a fix or is there just some small permission which I have to add causing it?