public abstract class MissingComponentException
This exception occurs when an attempt is made to dereference a reference from one
schema component to another, if the target of the reference cannot be found. Note that
an unresolved reference is not necessarily an error: a schema containing unresolved
references may be used for validation, provided the components containing the
unresolved references are not actually used.
10.0 - changed in 10.0 to be an unchecked exception