EDIT: this problem is now at my account too... so, it's a global problem then? This guy probably gets a lot of hits since all /contact pages in the Designer leads to this page: https://webflow.com/contact
I'm helping a colleague with a page shes building. For some reason, when in preview mode inside Designer, the buttons in the nav bar just opens a new browser tab with www.webflow.com/ ... (404 page) instead of navigating to the linked page inside the Designer. The nav bar buttons work fine in the published webflow.io subdomain page.
She did not have this problem earlier on in the project. The only difference I can see after the problemoccurred is that a customer is logged in to Editor mode...
(Yes, the styles and padding is a bit messy, I will help cleaning this up before launching)