If you run any program on port 15779, then you will have to use a proper Multiclient patch to bypass the port 15779 bind check the client does to prevent multiclient.
If you are using the latest ISRO 1.262 client, then you can just grab my

and use "Multiclient", "Redirect Gateway Server", and "NOP Hackshield" patches. That loader is more useful for development purposes and emu stuff because you don't need Hackshield running.
Otherwise, there are other loaders you can use to get around the check as well. That's the problem you are having though, the port is in use and Silkroad checks it.