The reference feature for this dimension has one of the following problems:
- The feature that the dimension references is missing.
- The feature that the dimension references no longer meets the validity requirements. For example, it is a planar surface that is no longer normal to the offset dimension.
- The dimension has been changed such that the model requires regeneration. For example, the tolerance mode for the dimension is set to Limits and the mean value of the limit values no longer matches the nominal dimension. In this case, Manage > Rebuild All is likely to fix the problem.
This condition also causes the dimension to be considered a failed object, as indicated by the additional message
Failed objects in the model. You can usually fix this problem by selecting a new reference feature.