Hello Geoff,
I am sorry to hear that.
It could be possible that the latest updates have failed to install completely or the connection with update server was interrupted. I would suggest you to uninstall the current version from the control panel and re install AVG- https://www.avg.com/en-in/download to resolve the issue.
If you face any difficulties, please provide the screenshot http://support.avg.com/SupportArticleView?urlname=How-to-create-a-screenshot of the error message to check and assist further.
Issue resolved (https://support.avg.com/answers?id=9060N0000000RtCQAU).
AVG Guru