Oracle Message KUP-04082 - error converting field string for LOBFILE column string

ERRORerror converting field string for LOBFILE column string
CAUSEThe LOBFILE column had either its directory object name or filename specified by a field in the data file and that field needed to be converted to the servers character set before it could be used. This message indicates that an attempt to convert the field failed.
ACTIONVerify that the data file has the correct value for the fields. Also verify that the correct character set was specified for the data file.