Thank you. That in itself did not help, unfortunately.
But I have now managed to get things running. The two underlying issues that appear to have caused my problems were
- The System Info binding; there appears to be an issue there, as expressed by a number of users here
- for some reason I still had a copy of openhab-addons-3.1.1.kar lying in my addons folder
After uninstalling the binding and deleting the *.kar file things appear to be running well now.