I have a WCF Service which returns 1000 records from database to the client. I have an ASP.NET WCF client (I have added service reference in asp.net web application project
Don't forget that the app.config of the execution entry point will be considered, not the one in class library project managing Web-Service calls if there is one.
For example if you get the error while running unit test, you need to set up appropriate config in the testing project.