Sys.ScriptLoadFailedException
Raised by the Microsoft AJAX Library when a script does not load successfully. This exception should not be thrown by developers.
Remarks
When a script does not load successfully in the browser, a Sys.ArgumentException object is created by using the Error.create function. The string "Sys.ScriptLoadFailedException" is specified as a name field value in the errorInfo object parameter.
For more information about how to handle error conditions, see Debugging and Tracing AJAX Applications Overview.