In reports/guided_reports.pl, when you do an export, there is a test for "$q_errors and @$q_errors", but in most cases $q_errors will actually be a hashref returned by execute_query and not an arrayref. 

I think this probably hasn't been caught because it's hard to initiate the Export phase for a report with errors, since it won't do the Run phase correctly.

But if you have a bad report and manually go to the export link, you can get guided_reports.pl to return a 500 because of the $q_errors data type being wrong.

Anyway, quite low severity, but raising it anyway...