Oracle Message ORA-19238 - XPTY0018 - It is a type error if the result of the last step in a path expression contains both nodes and atomic values

ERRORXPTY0018 - It is a type error if the result of the last step in a path expression contains both nodes and atomic values
CAUSEAn error occurred during the processing of the XQuery expression.
ACTIONCheck the detailed error message for the possible causes.