Stunstick being an error

hi i wonder if any1 can help me, when i pick up a stun-stick, whether single or multiplayer
it is an error sign. i have HL2 ep 1 2 and lost coast but still, it doesn't work. do i need the first half life?

wrong section please next time post it in the help secton thank you.

also there is already a simalar post https://edgecommunity.forumotion.com/t92-error-signs-and-pink-everywhere please look at it.