And it’s Nicola for the win…! I deleted the two tabular files and re-uploaded them and my code works! ☺ Following on from this does this error state happen very often or have I just been unlucky? If the former is true, any suggestions on how best to trap it and report back to user to fix? Thanks Nicola. I was beginning to wonder if I had blundered in my Python. Mark Fernandes T: +44 (0)1603 255000 Institute of Food Research, Norwich Research Park, Norwich, NR4 7UA, UK www.ifr.ac.uk Facebook | Twitter | LinkedIn | YouTube The Institute of Food Research receives strategic funding from BBSRC