Even though Team Fortress 2 is mounted and installed, the model for the bat appears to be an error.

I have the same problem, too. Plus, whenever I hold down left click and then press right click, the bat will start to randomly attack whenever I aim at an object, which makes it very difficult to aim and shoot things from the ground.

Another problem. For some reason, my bat decided to not hit enemies. Now, whenever I try to hit an enemy, it makes a metallic hit sound, instead, as if I hit an object (The NPC does not take any damage, of course). The only viable spot that I can hit with the bat is the feet (Not the legs, the feet, the bottom of the NPC). It happens on any kind of NPC, including the non-workshop ones.

i think bat disables ability to get hit by npcs
zombie tries to hit me and misses but if i literraly stand in front of him he will still miss

missing world model... it's the fact that the worldmodel has a bad name, it's not a valid one and thus, not seen as an actual model, it can be fixed by putting a fixed worldmodel from a different addon in the SWEP worldmodel