I don't know what's up , I still think my marshalling was correct , and to be sure I wil rather test the Marshall back and forth between two simple functions, instead of across the network session ,my suspicion is that the memmory is the problem across the session because I am not using two separate computers ,instead I am running the c# compiled exe and setting the one as server and other as client while one of them I execute in debug mode to catch any unknown exceptions from the debug break , if my test idea works then my suspicion might be on the dot .

other than that it's useless to keep worring about send_data , I wil just move on to other tests .