Why 50% of dimensions turn RED?

lloyd_snell

I have developed a casting model.
That model is derived to a part file for adding features for machining. 
I started a drawing so I could add dimensions and details as I develop features. Prevent missing important elements.
I then add two o-ring grooves and most of my prior dimensions turn RED. 
What do to do with red dimension?
Do I have to delete and start over?
Or is there a way to tell it nothing has changed?

NeilCooke

Dimensions in drawings reference edges or vertices which may change if adding other features that alter the topology of the face. If a dimension turns red you can select it and drag the orange dots on the end of the extension lines to point to the new geometry. This may be something you want to do towards the end of your design if their relative location hasn't moved.

NeilCooke

Dimensions in drawings reference edges or vertices which may change if adding other features that alter the topology of the face. If a dimension turns red you can select it and drag the orange dots on the end of the extension lines to point to the new geometry. This may be something you want to do towards the end of your design if their relative location hasn't moved.