The service cannot be activated

Error:
The service cannot be activated because it does not support ASP.NET compatibility. ASP.NET compatibility is enabled for this application. Turn off ASP.NET compatibility mode in the web.config or add the AspNetCompatibilityRequirements attribute to the service type with RequirementsMode setting as 'Allowed' or 'Required'.

Solution:
Add this line in top your Service class
    [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]