I'm at the part where you have to climb Clyde's fortress and when I go up to the second floor I can't properly aim at the tire swing with the bat with my ranged weapon or destroy the leg that leads to the ladder with my melee weapon. The cow is also still on the elevator.
I suppose this is a glitch because I defeated the nazi zombies and then went back down and defeated the enemies at the front of the castle. Whatever this glitch is though has ruined the game since I can't leave the backyard or (obviously) advance further up the castle. My whole game has been auto-saved as well so I can't load at a previous time.
I know I'm not the only one with this problem because it seems like a few youtube users have commented on a video with the same problem.