Oracle Solution for Error ora-19139

Solution for Oracle Error ORA-19139

ORA-19139: XPST0081: It is a static error if a QName used in a query contains a namespace prefix that cannot be expanded into a namespace URI by using the statically known namespaces

What triggered the Error:

error occurred during the processing of the XQuery expression.

What should we do to fix it:

eck the detailed error message for the possible causes.