I am getting an error when I try to add an ordinate dimension to a centerline.

"Cannot create this ordinate dimension. The selected entity has the wrong direction for the current ordinate group."

But this is clearly not true.

I can create a NEW ordinate dimension, but it dims it to the wrong end of the centerline... and will end up dangling the centerline dim for some reason.

Any one know how to fix this? This is the first time I have seen this problem.