Use of Undefined Structure messages that cannot be pre-defined
In general, XCom pre-defines the message to be used in the Configuration Tool and then checks the validity of the message.
By necessity, message structure is not fixed and message cant be declared.
In this case, undefined structure message is used.
Undefined structure Message is structure Does not validate against.
Set the Undefined structure message in the Configuration Tool.
All other messages are validated but not Undefined structure.