The error is in Crystal Reports or the code using crystal reports. My current theory is that it’s related to some kind of improper use of threading and Crystal Reports objects in the code. I’m rewriting most of my code relating to printing now making sure there is no possibility of different threads accessing the same objects.

I noticed also that Crystal Reports is filling up the temp dir with .rpt and .tmp files and first I thought this was the cause but even when making sure the temp-files are cleaned by my code I still get this.

It’s a pain to debug this as it seem to happen so rarely.