If a memory card is removed while in use, the device driver returns errors until the memory card is inserted into the appropriate socket. Close and reopen the device with the card reinserted, and the memory card will work.
If you remove the card while in use as a file system, unmount the file system using the umount command. Then reinsert the card and remount the file system using the mount command.
If you remove the card and interrupt a tar or cpio process, stop the process, reinsert the card, and restart the process.