after triing 2 weeks I am still not sure what the error was
(it wasn't something like missing brackets or semicolons)
I just reinstalled 3dgs and included the gstnet.h and it worked
(at the moment I wanted to show the error to a friend, maybe there is a reason always I want to show anything to anyone it doesn't work even errors dont accure)

But it worked 2h after my post...
thanks anyway