If a network event is sent to a PlayerObject's gameobject while there are other players in the instance it causes a unusual client behavior error.
In this instance the network event is initiated by a script on a gameobject separated from the PlayerObjects and is meant to enable the local player PlayerObject's gameobject/pickup that's currently disabled for everyone.
The moment the network event is sent to the targeted gameobject while there are other players in the instance, you get an unusual client behavior.