Duplicate Vat submission error message and script errors

SUGGESTED

On attempting to submit April Vat return, having granted permission, I encountered script errors but continued. I then got a submission error message, so repeated this, as suggested. The next time I got another error message stating that this was a duplicate submission.  When I checked the HMRC account my Vat return had not been received for April and was showing due, but still I keep getting the same duplicate submission error and script errors.  I do not seem to be able to submit via the Sage system at all.