PhotonView does not implement OnPhotonSerializeView()


I had to make an account as I didn't know where else to go. I have been on different discords asking for help with this error but none have replied.

I am making a simple 2d platformer/shooter through Unity.

I keep getting this error whenever I shoot another player:
"The observed monobehaviour (Bullet(Clone)) of this PhotonView does not implement OnPhotonSerializeView()!"

Ideally the health of another player is supposed to reduce on collision. The bullets collide but no health is taken away so I can only assume this error is the reason why.

I look forward to the replies and if further information or scripts are needed I would be happy to supply them.