ASUS is a great tablet, has a few issues but so do all, the main thing I dislike is there weak case design, it looks like the one you got was probably held a lot on that corner and the weight of the tablet started to bend the frame and pull on the glass causing the adhesive to let go, it looks like you can see the adhesive in the crack, You may be able to have ASUS repair it at your cost or try to seal it your self very carefully with some adhesive and a soft rubber tipped clamp.