Oracle Solution for Error ora-19228

ORA-19228: XPST0008 - undeclared identifier: prefix 'string' local-name 'string'

What triggered the Error:

e given identifier refers to either a type name, function name, namespace prefix, or variable name that is not defined in the static context.

What should we do to fix it:

x the expression to remove the identifier, or declare the appropriate variable, type, function or namespace.