XMLField object is already associated with XMLTable object. (Error 2144)

Visual FoxPro does not allow XMLField objects to be added to an XMLTable objects, XMLField collection, when they are already associated with another XMLTable object.

You can check to see if an XMLField object is already associated with an XMLTable object by checking its XMLTable property. If it is not associated, the value of the XMLTable property will be NULL. Otherwise, it will return an object reference to the owning XMLTable object.