Error every time game opens

So every time my game opens I get this error over and over again. I dont know what to do.

InvalidCastException: Specified cast is not valid.
Photon.Pun.PhotonNetwork.AlmostEquals (System.Object one, System.Object two) (at Assets/Photon/PhotonUnityNetworking/Code/PhotonNetworkPart.cs:2047)
Photon.Pun.PhotonNetwork.DeltaCompressionWrite (System.Collections.Generic.List`1[T] previousContent, System.Collections.Generic.List`1[T] currentContent) (at Assets/Photon/PhotonUnityNetworking/Code/PhotonNetworkPart.cs:1895)
Photon.Pun.PhotonNetwork.OnSerializeWrite (Photon.Pun.PhotonView view) (at Assets/Photon/PhotonUnityNetworking/Code/PhotonNetworkPart.cs:1775)
Photon.Pun.PhotonNetwork.RunViewUpdate () (at Assets/Photon/PhotonUnityNetworking/Code/PhotonNetworkPart.cs:1650)
Photon.Pun.PhotonHandler.LateUpdate () (at Assets/Photon/PhotonUnityNetworking/Code/PhotonHandler.cs:173)

Please help, I don't have any solutions!

Answers