How to change an endpoint address with XML Transformation in web.config?
Does the structure of your transformation file match your web.config? Specifically, are you missing a systems.serviceModel element?
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform"> <system.serviceModel> <client> <endpoint name="BasicHttpBinding_IService" address="NEW_ADDRESS" xdt:Transform="SetAttributes" xdt:Locator="Match(name)"/> </client> </system.serviceModel></configuration>