This error occurs if the data store did not return the requested Page.
This can happen in the following situations:
1. The specified Page does not exist in the database or is disabled.
You will need to login to the commerce manager and add a new Page or locate
the existing page and set it to enabled/visible.
2: The Page exists but customer does not have enough rights to access it.
Make sure the logged in customer or everyone(not logged in customer has
everyone role in the system) has enough rights to access the specified Page. To do that, open the commerce manager and locate the Page
in the site manager. Check the checkbox next to it and click "access" button. The
popup dialog will appear. Add "Everyone" role or specific customer with a "read" permission and click
save. Navigate back to the site. Please allow up to 5 minutes (depending on cache
settings) for site to work.