Error building Player: Exception: Error: type `System.Security.Cryptography.Rijndael` doesn't exist

Hi,

I'm trying to use photon chat in Unity 3D Game. While build for the windows phone/ WIndows Universal It shows follwing error.

Error building Player: Exception: Error: type `System.Security.Cryptography.Rijndael` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at Photon.SocketServer.Security.DiffieHellmanCryptoProvider.
Error: type `System.Security.Cryptography.Rijndael` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Boolean Photon.SocketServer.Security.DiffieHellmanCryptoProvider::get_IsInitialized().
Error: type `System.Security.Cryptography.RijndaelManaged` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Void Photon.SocketServer.Security.DiffieHellmanCryptoProvider::DeriveSharedKey(System.Byte[]).
Error: method `System.Void System.Security.Cryptography.RijndaelManaged::.ctor()` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Void Photon.SocketServer.Security.DiffieHellmanCryptoProvider::DeriveSharedKey(System.Byte[]).
Error: type `System.Security.Cryptography.Rijndael` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Void Photon.SocketServer.Security.DiffieHellmanCryptoProvider::DeriveSharedKey(System.Byte[]).
Error: type `System.Security.Cryptography.Rijndael` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Void Photon.SocketServer.Security.DiffieHellmanCryptoProvider::DeriveSharedKey(System.Byte[]).
Error: type `System.Security.Cryptography.Rijndael` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Void Photon.SocketServer.Security.DiffieHellmanCryptoProvider::DeriveSharedKey(System.Byte[]).
Error: type `System.Security.Cryptography.Rijndael` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Void Photon.SocketServer.Security.DiffieHellmanCryptoProvider::DeriveSharedKey(System.Byte[]).
Error: type `System.Security.Cryptography.PaddingMode` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Void Photon.SocketServer.Security.DiffieHellmanCryptoProvider::DeriveSharedKey(System.Byte[]).
Error: method `System.Void System.Security.Cryptography.SymmetricAlgorithm::set_Padding(System.Security.Cryptography.PaddingMode)` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Void Photon.SocketServer.Security.DiffieHellmanCryptoProvider::DeriveSharedKey(System.Byte[]).
Error: type `System.Security.Cryptography.Rijndael` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Byte[] Photon.SocketServer.Security.DiffieHellmanCryptoProvider::Encrypt(System.Byte[],System.Int32,System.Int32).
Error: type `System.Security.Cryptography.Rijndael` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Byte[] Photon.SocketServer.Security.DiffieHellmanCryptoProvider::Decrypt(System.Byte[],System.Int32,System.Int32).
Error: type `System.Net.IPHostEntry` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Net.IPAddress ExitGames.Client.Photon.IPhotonSocket::GetIpAddress(System.String).
Error: type `System.Net.Dns` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Net.IPAddress ExitGames.Client.Photon.IPhotonSocket::GetIpAddress(System.String).
Error: type `System.Net.IPHostEntry` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Net.IPAddress ExitGames.Client.Photon.IPhotonSocket::GetIpAddress(System.String).
Error: method `System.Net.IPHostEntry System.Net.Dns::GetHostEntry(System.String)` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Net.IPAddress ExitGames.Client.Photon.IPhotonSocket::GetIpAddress(System.String).
Error: type `System.Net.IPHostEntry` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Net.IPAddress ExitGames.Client.Photon.IPhotonSocket::GetIpAddress(System.String).
Error: method `System.Net.IPAddress[] System.Net.IPHostEntry::get_AddressList()` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Net.IPAddress ExitGames.Client.Photon.IPhotonSocket::GetIpAddress(System.String).
Error: method `System.Void System.Net.Sockets.Socket::set_ReceiveTimeout(System.Int32)` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Boolean ExitGames.Client.Photon.PingMono::StartPing(System.String).
Error: method `System.Void System.Net.Sockets.Socket::Connect(System.String,System.Int32)` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Boolean ExitGames.Client.Photon.PingMono::StartPing(System.String).



Anyone found solution for this???

Unity version : Unity 4.6.X