Font manager functionality requires a google API key, it's included by default with architect, but you might want to replace it with your own at some point to avoid issues.
Open this url https://console.developers.google.com/project and click on Create Project button.
Enter your project's name, accept the terms, click create and wait until your project is created.
Click on APIs & auth on the right and make sure Web Fonts Developer API is enabled (ON).
Click Credentials on the right, click Create New Key, click Browser Key and finally click Create. You can leave ACCEPT REQUESTS FROM THESE HTTP REFERERS (WEB SITES) field empty or enter your site url.