If you use any error templates to specially-handle Fusebox core file error, be sure to put them in a sub-directory off the root of your apps called "errortemplates". Fusebox will look for them here, as files that are named the same as the error to which they refer, in the form "[FuseboxErrorName].cfm", where FuseboxErrorName corresponds to the error type generated by the Fusebox core file. Examples are "fusebox.failedAssertion.cfm" and "fusebox.circuitXMLError.cfm". Modify the sample error templates files included in the core file distribution as you see fit. Alternately, just rename or delete them and the natural error(s) thrown by the Fusebox core will be thrown.