I am using lenovo A7-50 tablet for past three months and having 16 gb memory card.i have installed apps from google play.i moved some apps to sd card via settings->apps .One time i switch off my tablet and switched on again, my tablet showed "damaged sd card image" and the apps which i stored in sd cards are gone.I switched off tab and removed sd card inserted again.power on tab, i can see my sd card storage and all the apps are gone.i can see new sd card formatted.Again i have downloaded apps and moved to sd card.again i switched off my tab same "damaged sd card "message came.i removed and re inserted sd card after switching off the tablet.Now its showing formatted sd card, all apps are gone.whats is the problem?