Oracle Message ORA-19227 - XPTY0007 - fn: data function is applied to a node (type (string)) whose type annotation denotes a complex type with non-mixed complex content.

ERROR	XPTY0007 - fn: data function is applied to a node (type (string)) whose type annotation denotes a complex type with non-mixed complex content.
CAUSE	The input node for atomization contained a type annotation that denoted a complex type with non-mixed complex content.
ACTION	Fix the input expression to fn: data to be a node that does not contain non-mixed complex content.