I see error messages stating "no fault routes were found to be configured" in the logs. I have googled this, in hopes of finding some dokumentation, with no success. I suspect it is some way creating exception handling in the process. What does this mean? How do I configure these "fault routes"?
Yes , event handling can be done using default exception event(as you rightly caught flash with a circle) as well , but it will handle limited exceptions only for ex: GeneratePDFOutput2 provides you with SYSTEM and OUTPUT exception only by default.
If you try to record the process and at the point where you get the error, you must able to trace the reason behind it. An indicating reason may give you an idea what is causing the workflow to obstruct.