Invalid field: Created By ??

In the Business template, any edits I make to the Home Page Carousel page results in an error, "Invalid field: Created By" -- but it does not say what the error is. This happens even when I open the default page and try to save it. 
See Snapshot here  bryj4.com/images/0-HJT/Invalid-Field-Message.jpg
Can you please suggest a solution? 

Hello,

To solve this, go to the Publishing tab, click the User icon in the "Created By" field, and click your user name. Finally, save the article.

Regards,
Milos