Your checkout workflow is empty.
Checkout workflow invalid. The modification is ignored. See the documentation for more information on how to configure that option.
Please note that in some cases this error can happen even though the checkout workflow is correct and it due to a user session issue. To solve the problem, please clear your browser cache and cookies and it should solve the problem.
No valid weight unit entered. The system put back the default units.
No valid dimension unit entered. The system put back the default units.