Thanks for reaching out to the community, allow me to help you with your concern today.
Going from experience, this error usually occurs when there is an issue with your domain. In order to help you with this, could you please share the store URL that shows the error and also a screenshot of your domain settings if you can. To find this, go to Settings > Domains in your admin. This will help me troubleshoot effectively for you.
Have you made any changes to your domain settings recently? For example, you may have tried to connect a third-party domain to Shopify? If you did, how long has it been since you connected it?
Let me know, looking forward to your reply!
Maz | Social Care @ Shopify - Was my reply helpful? Click Like to let me know! - Was your question answered? Mark it as an Accepted Solution - To learn more visit the Shopify Help Center or the Shopify Blog