I am trying to bring May statements electronically into the new financial year however I'm getting error messages
ERangeError: Date (...) is not within a current open year
I assume I have to 'open' the previous year again somehow?? Any ideas?

@Clare-Johnston yes - you will need to open your 2018 financial year - to do this go to Tools - create new year. You are able to have two financial years open at a time - so keep your 2017 year open while you tidy up the rest of the year