Setting Up Public Gateway won't allow server to start

Hi everyone. So I’m trying to finish setting up my Public Gateway. I’m having a small problem that is causing a couple issues I need resolved. So I "m trying to add the below to my config file. When I restart IPFS with the below it will not start. When I remove this it works fine but I cannot get the subdomain features to work because of it. I’m using go-ipfs 11.

"PublicGateways": {
        "gateway.mydomain.com":{
                "Paths": ["/ipfs", "/ipns"],
                "UseSubdomains": true
                }
        }