the body tag error you are receiving is normally due to HMRC not expecting filing type being submitted. Can I please confirm the step by step process which you are using to submit to HMRC.
Thank you
Thank you for your help- I was trying to submit through Reports (like I have always done but selecting 'file online' rather than 'file manually' because I had tried to submit through 'File VAT MTD' but the box showing the next stage did not appear to offer anything other than VAT Obligation and which return to select. Also a Cancel button.
Anyway, I have just tried stretching that box and discovered a 'Proceed' button on the very, very far left which then took me to the Declaration and Filing!
Hope this helps others.