When a user is creating a new page and leaves a mandatory field blank, the system does not provide a warning message that is neither in an expected location nor informative as to where to fix the error. Normal expectation is for the warning message to appear as a pop-up in the center of the screen and provides information on what caused the error so that users can quickly go to the field(s) to be fixed.
Current experience is a notification drop down in the upper right corner that fades away. Since it is not persistent, the user may not notice it at first and miss the actual notification. To add to that, if one does notice the notification, the error message is not simple or insightful as to what the issue is and how to resolve it.