A couple weeks ago we patched our Jaspersoft Report server to the latest patch (6.2.1_126.96.36.199).
Of course we got bit by the Scheduled Reports are Blank bug (CA: DE32148, Tibco: 01467237).
No worries, I went into every scheduled report and clicked save - all those are back and running properly.
I have one outlier: a custom Jaspersoft Studio report that no longer returns data. I believe the patch was the last event before this stopped working. The Jaspersoft Log is not showing any trouble.
It feels like one of those 'remap a GUID or Bean' thing. I believe I've executed all the necessary post patch commands properly. I can open a ticket but if this is an easy fix it would be great to capture it here for the next forum traveler.