Is there a more specific indication regarding access to what is denied? Any chance you can share (a relevant part) of your logfile?

It doesn't seem to get far - 100 lines in I get this -

I'm not sure if you meant to paste or attach part of the log, if so, it didn't show up.

100 lines in is pretty early on indeed, my bet is that it's a reader that's causing it. If you have multiple readers in the workspace you can try disabling them one by one to see if you can narrow it down to which one it is.

@Hans van der Maarel​ thank you, sounds sensible, I'll try to narrow it down.

I see you're using TransporterSender/TransporterReceiver, that does add some complexity to it. Are those pointing to the same machine, or another one?

Thank you for your help. Stepping through the separate processes, disabling one at a time I found the problem. I was calling a PDF Formatter - have now changed the workbench to include the PDFPageFormatter within the workbench. Now works!