Help! NpcGlitch

Help,

Npc’s is my game like Zombies,Combine,Animals. walk right through me also when a hunter’s dart hits me it goes right through me.

Zombies can’t hurt me and Roller mines go right though me.

i need help I didn’t mess with the lua or config

i have deleted my garry’smod folder and let it reinstall itself. But the glitch was still there i have also defagged my gmod and Ran v-cache Fix and it did nothing.

help!!!