I use Google Chrome without any issue today.
Is it blocked at login or slow with disabled features as described here : Have you been experiencing significant difficulties using the community for the past 2/3 days?
Your issue is that you're trying to access a domain which doesn't exist. There is a forward-slash missing between .com and the 3 in your URL. You're probably accessing the page via a bad auto-completed URL. You should be fine if you navigate directly to nation.marketo.com in Chrome.
What did you use to get to nation.marketo.com in the first place? The URL in your address bar does not end in a ".com" try using "https://nation.marketo.com/welcome".
I'm clicking on the 'Community' button available within the Marketo instance and I'm being shown the error message. I thought this was because of a VPN issue and I retried after disconnecting the VPN and still the same issue.