The inputClassDescriptor method of ObjectInputStream traps ClassNotFoundException and NoClassDefFoundError. However, catching the NoClassDefFoundError results in an error propagation such that the
name of the original missing class is normally lost, and only the top
level class is reported as missing.

This can be reproduced with a simple RMI server which is restricted to
using it's own codebase. If the interface for the server contains a class
which is not in the RMI client's classpath, when Naming.lookup is called,
the registry will fail to locate the missing class. However, the exception
thrown will report that the server's Impl class is missing.