Sorry, I’ve only just seen your reply.
I set things up like this:
I put in my group stages with all the results and THEN I set up the 2nd round and so on. When I tried to put the results in I then got the error as subject.
I think what needs to happen is you need to set up EVERY ROUND of the competition first BEFORE putting in any results. Once you put in all the first round results the system then automatically creates the 2nd round.
Because I’d put in all the group stage results first it didn’t do this – so I resubmitted a group stage results page and it then worked as intended.