This message is displayed when you are recording a test and trying to perform any action over a Silverlight application that was prepared for testing using the tcAgPatcher.exe utility’s version which is not supported by the current version of TestComplete, or when you are trying to use the target glyph with such an application. The tcAgPatcher.exe command-line utility is shipped along with TestComplete and is installed to the <TestComplete>\Open Apps\Silverlight folder by default. In order for TestComplete to get the access to internal objects, methods and properties of your Silverlight application, its package file (the .xap file in which the Silverlight application’s functionality is implemented) must be processed with tcAgPatcher.exe.
Note that you must process your Silverlight application’s package file by using the tcAgPatcher version shipped along with your TestComplete package. If the application was processed with a version of tcAgPatcher.exe other than that shipped along with your TestComplete package, the TestComplete test engine cannot obtain access to its internal objects and their members. In this case, you can test your Silverlight application only via the functionality provided by the UI Automation engine just as if your application was not processed by the tcAgPatcher.exe utility at all.
To better learn how to prepare your Silverlight application and make it “open” to TestComplete, see Preparing In-Browser Silverlight Applications for Testing.