In a Wizard with form integration, once you click on the "Done" button, the form is posted to the server, if the server returns the page with any errors in the ModelState, the wizard is displayed again from the first step and any errors are added to their respective fields.
The problem is that if the errors are not in the first step, the user simply sees the Wizard returning to the first step with no obvious indication of why. Only when he navigates to the next steps he will understand that an error was found. If the Wizard has many steps and the error in only in the last ones, the user can get confused.
It would be nice if the wizard could display an icon/badge on top of the step icon indicating that an error was found in that step.