I made it to the northern airfield, suddenly I see a lone zed in front of me. Can't take out my weapons even though I can move around, take out my fists, punch, open inventory, etc. Zed doesn't move, but when I press tab I see I'm bleeding (no other zeds or people around, I was not bleeding or otherwise hurt before). Close the game, re-open, suddenly I'm dead and I respawn along the coast.