Looks like a 'update-notifier' issue, not able to get the required 'EULA' popup to validate the installation. So the server used may have some restrictions or misconfiguration.
Some users have suggested, as a workaround, to try with different DNS.
Myself have had such issue; but i've made a fresh installation (due to some not related troubles) and now the whining popup is gone. That is, so the 'EULA' problem can also be an user borked configuration.
Looks like a 'update-notifier' issue, not able to get the required 'EULA' popup to validate the installation. So the server used may have some restrictions or misconfiguration.
Some users have suggested, as a workaround, to try with different DNS.
Myself have had such issue; but i've made a fresh installation (due to some not related troubles) and now the whining popup is gone. That is, so the 'EULA' problem can also be an user borked configuration.