Hello Paul Connolly,
Welcome to Microsoft Q&A forum.
Before we proceed further, may I know if your license is tied to your Microsoft account or an OEM license? Additionally, may I know what happen when you go to Settings > System > Activation and choose "I change hardware on this device recently"?
If possible, may I have a photo of the error to check for you? Please remember to remove all personal information before posting.
I'm waiting for your reply.