The condition class
field-access-exception is a subclass of field-exception.
field-access-exception is signaled when an attempt to access a field gets an exception. This can occur for various reasons, for example the new value that was passed for setting is not an acceptable value.
You can use the field-exception readers
field-exception-field-name on conditions of class
LispWorks User Guide and Reference Manual - 13 Feb 2015