Cannot connect to my own local server ~ "Unique ID not valid"

I’m using the Dedicated Server Launcher app found on this forum to set up a server on my local machine. I was able to get friends to connect but when I try to connect, I get rejected with the error “Unique ID not valid”.

I know this is typically caused when you run a steam game server locally and then try to play the game on the same machine. I’ve seen people typically get around this by running the server with in a .bat file and the option -nosteamclient or -nosteam. My problem is since I’m using the Launcher app above, I don’t know where to add that parameter. Any ideas where I could add that or any other ideas that may cause this error?

Thanks in advanced,