isisaddons/isis-module-excel — pull request #4 by oscarbou (2014-08-30 15:14:16+00:00)
Title: ExcelService.Exception should be a RecoverableException

As for Isis help:
Indicates that an exceptional condition/problem has occurred within the application's domain logic.
This exception should only be thrown for "recoverable" exceptions, that is, those which could be anticipated by the application