I used to be able to highlight & click world canvas GUI elements, like buttons, using a locked, hidden & centered cursor. This simulated using the camera's view as a pointer. It doesn't seem to be working anymore in 5.4.0f2. GameObjects still respond as expected using MouseOver & MouseDown. When the cursor is visible, the GUI buttons work fine (but I want it locked & hidden). I'm submitting a bug report now. Any ideas?