Return of Reckoning

Hey guys, im getting this error

Error: System.IO.IOException: Incorrect function.

at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at System.IO.FileStream.ReadCore(Byte[] buffer, Int32 offset, Int32 count)
at System.IO.FileStream.Read(Byte[] array, Int32 offset, Int32 count)
at System.IO.BinaryReader.InternalReadChars(Char[] buffer, Int32 index, Int32 count)
at System.IO.BinaryReader.ReadChars(Int32 count)
at WarZoneLib.MYP.MYPHeader.t46LS5jvS6nWpHSBfks(Object , Int32 )
at WarZoneLib.MYP.MYPHeader.Load(BinaryReader reader)
at WarZoneLib.MYP.hUi4NUawJNVEThRBuW(Object , Object )
at WarZoneLib.MYP..ctor(String fileName, FileAccess access)
at WarZoneLib.MYPManager.Get(MythicPackage archive)
at RoRLauncher.Client.gGUhKmcY0MwYwiWiANN(MythicPackage archive)
at RoRLauncher.Client.Handle(PacketIn packet)
at RoRLauncher.Client.uVm3RMckDq5gW3822Li(Object )
at RoRLauncher.Client.OnReceive(PacketIn packet)
at RoRLauncher.Client.sQFFQNc4xaG4Xv8fcHj(Object )
at RoRLauncher.Client.tkeprHWAcH(Object )

and its not letting me launch the game, anyone know whats up?