This just happened again a few days ago. In between my OP & now, 10's of thousands of invoices have been exported to PDF just fine. At the end of last week a device attached to a server that some reports (not the invoice PDFs) are saved to locked up that server. This seemed to put the app into an unstable state & it did the "export several hundred bad PDFs" thing again. However - no error messages this time - the app just sat there not responding & the user had to end task (after waiting 15+ minutes).

I just don't know where to go with this - how I can figure it out, how I can prevent it, etc. The customer is most definitely unhappy & (surprise, surprise) I hear about the unhappiness.

I may have to isolate this printing process on its own VM - but that means more licenses & work.