Account Type Status Change Rules; fails to send SMS Document

When an Account Type Status Change Rule is linked to a Document that sends an SMS the following error occurs:

Failed to execute Status Change Rules for Account 'xxxx'.
Failed to action Account Type Status Change Rule 'xxxx'.
Failed to save Account Log.
Extended data does not contain any Email recipients (either 'To', 'CC' or 'BCC').

The Account Log that was generated was mistaken setting the extended data type to "Email".