Hello,
Did you find a solution ?
I have the same problem. My code work on Windows but not on linux i can't pass Socket.AddMulticast(). If i use the debugger on TUDPBlockSocket.AddMulticast(MCastIP: string), it block on Multicast.imr_multiaddr.S_addr := swapbytes(strtoip(MCastIP)). Error message : RunError(201).
I use this code for UPnP, i have an other UPnP program build with MiniUPnP and it work perfectly.
Thanks.
@+