DrByte thanks a lot.

It was a case of I couldn’t see the wood for the trees

What I had actually done was renamed create_account to create_accountold and copied in an unmodified version from another site to see if that was the problem.

I was stumped when I got what I thought was the same error message, not noticing it was continuing to look at the old version even though it had been renamed. It obviously looks for "create_account" regardless of any additions to the name?

Deleting that old renamed file has fixed the issue, thank you.