Hi @bobray …
Thanks for taking a look.
I’ve actually worked around this issue by forcing the creation of a secondary CSV file via the snippet itself. So all is good.
However, I wanted to test this and you were spot on. The CSV resource was in an admin-only resource group - taking it out of this group allowed my original code and @markh code to do what they should.
I should note that the PHP file-exists function still returns false - but as @halftrainedharry said, I don’t think that’s wholly relevant.
It’s good to know that this can be made to work.
Thanks again all for helping.
Chris