Domain name change
One common cause for this error is switching your primary store domain to a custom domain: for example, from store.myshopify.com or store.mybigcommerce.com to store.com.
When this occurs, our servers don't automatically detect that you’ve changed your domain. Contact our support team for assistance.
Dismissing the popup
If you dismiss the popup, it will temporarily disappear. To view the popup again, open up your site in an incognito window.
Browsing in an incognito window disables any past history or cookies, allowing you to view your website from the perspective of a first-time visitor. How you open an incognito/private browsing window depends on the browser you're using, but here are some common methods:
In Chrome, go to File and select New Incognito Window.
In Safari, go to File and select New Private Window.
In Firefox, go to File and select New Private Window.