The screen will not attach to the wall mount. What should I do?

• Make sure the screen is not upside-down and make sure the wall mount isn't attached upside-down. The slotted hole should be at the bottom.
  
  Press the screen firmly onto the wall mount, with the hooks on the mount aligned with the holes in the back of the screen; then lower the screen onto the hooks. Make sure the four hooks are engaged, so the screen is securely attached.