"The window is disabled. The action cannot be executed" in log file while test runs successfully

Hi,

I'm using keyword test for WPF application. I have a largetextbox over a popup window. Each has unique automation id. My scenerio includes entering string into the largetextbox. Test runs successfully (string could be entered into the largetextbox) but in test log an error occurs ("The window is disabled. The action cannot be executed"). I don't understand why this error occurs. Test seems to have failed.