If problems occur with rooms in a model, Revit provides explanations in dialogs, room tags, or room schedules.
When an error occurs, you can select the tag or the schedule row that displays the error, and click Modify | Room Tags tabWarning panelShow Related Warnings or click Modify Schedule/Quantities tabError panelExplain Error.
Revit shows the message that it displayed when the problem first occurred. You can use standard error dialog features (like Show) to find the relevant tags.