Oracle Solution for Error ora-19138

ORA-19138: The target type of a cast or castable expression must be an atomic type that is in the in-scope schema types and is not xs:NOTATION or xs:anyAtomicType, optionally followed by the occurrence indicator "?"; otherwise a static error is raised

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.