Oracle Message ORA-19228 - XPST0008 - undeclared identifier: prefix string local-name string

ERRORXPST0008 - undeclared identifier: prefix string local-name string
CAUSEThe given identifier refers to either a type name, function name, namespace prefix, or variable name that is not defined in the static context.
ACTIONFix the expression to remove the identifier, or declare the appropriate variable, type, function or namespace.