dimensions in dangling status

A drawing set which contain only 1 part and 3 view (top,side, front). It doesn't allow me to delete but hide dim. only.When I add a dimension it becomes red (dangling status). By the waythe icon is in manager tree on the left is shown the broken linkand I don't know how to update that. (see attached file)
TIA for any help or/and commentSolidworksGeneral