When you have mutlitple bindings in IIS and have a WCF Service defined you may get the bellow error:
“This collection already containes an address with scheme http. There can be at most one address per scheme in this collection.”
This happens when you have mutlitple bindings on the IIS Web Site i.e. HTTP and HTTPS.
If you have .NET 4.0 installed and are on Server 2008 or later you can add a directive to your web.