City completely dark – lighting/rendering bug

It happened after 2.0 update ,on 28th January ,in meantime I upgraded all tasks ,it costs about 4.000.000 Simeleons and about 200.000 Neos .All Sims are happy now ,City is about 3.500.000 in total ,I can see Buildings only when I press some upgrade ,Traffic etc .I have some old Ipad ,I shall try to transfer City in a next few days ,I shall let you know is it helpfull .