If errors occur with an SMS application, use the error logs to help debug the problem.
To access the error logs, go to the SMS Applications heading and select 'Error Logs'.
The log table will populate with any errors that occurred within your application. For more details on a specific error, click the 'View' link on the right side of the table.
There, you'll be able to see the error that was generated, including the SMS request, the XML response, and highlighting the line of code that's causing the error (if applicable).