On left pane in editor, you'll see various service elements already defined. Click on your Service Endpoint node. 90% of time root cause of this error will be hanging around this Service Endpoint definition.
Remember, all the WCF service configuration definition is found under
Here's the checklist that should help resolve this error.
- Confirm your Contract attribute of Endpoint element is pointing to appropriate Service contract instead of "IService1" unless you are still using "IService1" as service contract.
- Confirm your Name attribute of Service Element is set appropriately to Service class implementation instead of "Service1" unless you're still using "Service1" as service implementation.
- Also, Examine ServiceHost directive declaration in service1.svc markup. Clean up any scrap you see and provide fully qualified namespace for the service class for service attribute.
I strongly recommend you use Service Configuration Editor for any kind of poking around web.config/app.config related to WCF service. This way, you'll keep service configuration neat and clean. especially with complex configuration files, this tool will come handy in organizing the service elements easily.