my tablet using andoid 4.1.1 refuses to believe there is a sd card so cannot use the camera etc. If go to settings and click storage settings closes with the message 'settings has closed'. All other functions of settings works. if go to file manager it says 'directory is read banned' when try to go to external sd card files. if touch external sd card messge 'file does not exist' occurs. if hit the up icon also, hit gallery and message ' file does not exist' occurs. i have even hit the reset button back to factory settings with no help. any ideas out there?