Adobe ILLUSTRATOR 6.0, Online Manual, Page: 801 / 893

801
Anchor points cannot be selected.
The object is locked, or there is another
anchor point on top of the anchor point
you want to select.
If you think that the object might be
locked, choose Arrange
>
Unlock All.
(Make sure that you unlock each layer
individually; Unlock All unlocks only
objects on the current layer.)
If you still can’t select the anchor point,
select the path that is on top of the path
containing the anchor point you want to
select, and lock it. Select (and adjust as
necessary) the anchor point you have
been trying to work with. When you
have finished, choose Unlock All again.
Another solution is to select both
anchor points by dragging, hold down
the Shift key, and click to deselect the
front point.