Zoho Projects - Zoho Books Sync Error "This project is associated with unapproved report(s) hence customer cannot be changed."

Zoho Projects - Zoho Books Sync Error "This project is associated with unapproved report(s) hence customer cannot be changed."

What does this error mean and how do I fix it: "This project is associated with unapproved report(s) hence customer cannot be changed."

As show on the screenshot below this happens between the integration between Zoho Projects and Zoho Books