Model-Based Definition > Geometric Dimensioning and Tolerancing Advisor > Advisor Message Help > DRF Messages > The DRF Is Invalid
The DRF Is Invalid
The referenced datum features do not represent a valid DRF case. This problem was probably caused by modifications to the design model that changed the relative locations or orientations of the datums. This problem causes the DRF to be considered a failed object, as indicated by a separate 'There are failed objects in the model' message.
You may be able to fix the problem through the following procedure:
1. Right-click on the DRF in the Feature Tree and select Edit... from the context menu.
2. In the Edit DRF dialog window, reselect datum features to define a DRF. The application only allows the selection of datum features that form a valid DRF.
3. Click the OK button in the Edit DRF dialog window.
For more information, see Add DRF (ASME) or Add DRF (ISO) in Model Based Design > Geometric Dimensioning and Tolerancing Advisor > GD&T Advisor.