For some reason I cannot dimension to a hidden line in a drawing. The only item I can select for a dimension is a tapped hole. If I try to dimension to a bore or a rib that is on the far side of the object I cannot select the hidden line. This just started happening today as far as I know. I checked another computer here and it is doing the same thing.

I can bring up drawing I did a week ago and there are dimensions to hidden lines on them, but if I try to add one, even duplicate one that is already there I cannot select the the hidden line.

Any thoughts?