Oophs the access token has not been authorised message

I have gone into the client and tried to post the VAT return and get this message. When I log into data dear is says the clients I have have never been used and then says 6 returns or 1 return etc something is definitely wrong.

I have spoken to HMRC and they say everything is ok so what is going on - this happens every time I post a vat return for my clients - I have to reload them and then it still does not work
Getting very frustrated as I have 5 clients all with different months VAT so its a regular problem.

Please can you explain this - if Revenue says there is no problem why do I get this like others have too ? see previous topics.