When your license expires you will not loose access to your passwords, you only loose premium features which counts Password guardian and One touch login all other features are free and will be available even after license expiration.
If you can't access your passwords within the application (you see endless rotating spinner) then most likely you are facing an issue in our update process and you have still old version of GUI with new version of Avast. This should get fixed after reboot, if not then repair is claimed as 100% working solution for this case.