This error indicates that your DSS instance does not have access to the following Internet URL: https://update.dataiku.com/.
Can you confirm that your machine has Internet access and that you can connect to this URL on your browser?
You may need to whitelist *.dataiku.com on your proxy or firewall.
Hope it helps,
In that case, the tutorial loading should work. Could you retry once more after refreshing your browser page, please?
If the issue happens again, could you please send us the content of your browser "Inspect console" (Right click > Inspect)?