Sketch references

[Marie]

When I try to add a new reference and dimensions to one of the sketch lines. It does not allow me to add any references or delete existing ones. I tried the edit references, but that only lets me change existing references.
"References to additional 3D geometry may not be made" is the error message when I try to add a reference.
Any suggestions!

[Abraham]

It normally happens when you have that particular feature mirrored, and if your feature is being mirrored or copied elsewhere (I assume patterned as well), you cannot delete or change the references. Once you delete the mirrored instance the problem will be solved.