Unhandled Exception: System.ArgumentNullException: Argument cannot be null.
Parameter name: value
  at MonoTouch.iPhoneSimulatorRemoteClient.DTiPhoneSimulatorSessionConfig.set_SimulatedSystemRoot (MonoTouch.iPhoneSimulatorRemoteClient.DTiPhoneSimulatorSystemRoot value) [0x00000] in <filename unknown>:0
  at MonoTouch.Simulator.SimController..ctor (System.String app_path, System.String sdk_version, System.String device_type, System.String[] args) [0x00000] in <filename unknown>:0
  at MTouch.Main (System.String[] args) [0x00000] in <filename unknown>:0