Default Transfer files to s4 Active

HI all, i bought galaxy s4 active after many android devices, now when i try to move a game data files to OBB folder in internal memory it said can't move or copy files. i put it in another folder and from the device itself tried to move them to OBB ,also say copy or move failed. what's the problem here ?? before i had a LG 4X and its easy to transfer data of games and apps, but here i can't