If you are working with equations from SolidWorks 2011, you might encounter errors in the Equations dialog box if both of the following conditions apply:
- A part or component referenced by the equations has multiple instances in the model.
- The equations are linked to an external file.
The instance numbers are not initially reflected in the external file. To resolve this discrepancy, update the external file by exporting the equations to the external file and rebuilding the model.