Nexus 4 Proximity Sensor Fix. Somehow this worked for me as well, which makes no sense but whatever...

The proximity sensor was not working causing the screen to stay black during making/receiving a call. I googled it and found out it is a pretty common issue after screen replacement and the only workaround was to put some very thin clear tape or a small piece from a screen protector, between the front glass and the proximity sensor. I tried that for a fair amount of time but with no luck. So i tried to put the small rubber piece that covers the light and proximity sensor the opposite way. Now the bigger hole of this rubber piece is on the small sensor (proximity) and the small hole is on the big sensor (light). It worked right away and still works great after a month