Android Camera App complains "Please insert an SD card..." Today my Android phone running Oxygen Rom 2.3 could not make photos any more. A error message appeared on opening the camera app: "Please insert an SD card before using the camera", although the sd card was present and also detected by the system. When mounting it on my Linux system, I could not delete any files and the error appeared: "read-only file system". A little research revealed, my fat32 filesystem got corrupt somehow, but this can be easily fixed: sudo fsck.vfat /dev/mysdcard -v -r (please unmount the partition before and change /dev/mysdcard to the value of your device! you can see all your mounted partitions with running the "df" command!) On Windows, You need copy all of you content to your pc and format you sd card and copy back the content. Then insert the SD card into your phone, it should work.