Hello ,a couple of days ago my tablet started playing funny and changed the wall paper to a diferent one than the one downloaded and chosen for me, as this was no a big issue I ignored it. Then this morning the tablet changed the display completyely and now I do not seem to find anywhere the three main icons on android devices screens these being the curved arrow to go back, the square arrow like to go to the main screen and the one to change between apps so I do not seem to be able to get out from an app once in it . Also neither the wall paper or the screen with all the apps are able to rotate and only stay vertical and not horizontal. Does anyone know what is going on with my tablet? Thank you in advance.