Fix error messages on failed data load
Fix error messages on failed data load

Overhauled error handling to report multiple failures. Fixed a bug where error handling just utterly failed on the first problem.

htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor