I have tried to look around on the forums before I posted this, Now I am posting this....Whenever I try to revive someone, Nothing works. I have tried on multiple occasions sometimes in LCPDFR other times in regular gameplay...I have tried both Single and Multiplayer and I have even tried to switch my keys. Whenever I click ALT-M infront of a person, it wont revive them, I have tried changing it to ALT-R and ALT-Q and I have even tried using the LALT and RALT but neither work..

You will very rarely be able to revive someone. There is a % chance "roll" which I normally don't get. But once in a blue moon if someone does under certain conditions (no assault rifle or shotgun, not in the face, not rolled over with a car) they will limp away instead of dying in the street.

Everyone else that I play with can revive ANYBODY 24/7......

They're probably playing version .91. The .95 beta has a new revival system that has a % chance. .91 was 100% like you said.

Just call for an ambulance. In real life the police isn't there for reviving but they can give CPR until medical personnel arrives with equipment that they can use.