unity game stuck/crash on few mobiles in start

I have created a game and available on google play Game Link. On several mobiles it is working fine. The problem is that with some devices like HTC one and Samsung grande it’s screen is half the size. Additionally no sound is coming and it seems it is stuck/crash.
I am sure that unity developers would have faced this problem.
Feature includes :

  1. obb (game size : 111 MB)
  2. data storage on sdcard
  3. new UI
  4. admob

I have bit different problem with UI on different size of screen. In the image attached from samsung grand mobile. You can see the main screen seems to be split in half. It is not in the case with HTC desire C, which I was using as primary cell phone.

Next scene, you can see the background is half while button is at correct position. Background in second image is

Next scene the game, it is normal on every mobile