Cannot select certain vertices Blender 2.79



No matter which mouse button I click, I cannot select or deselect any of the vertices on a curve. This seems to also apply to when I am editing vertices on a mesh and "Limit Selection to Visible" is disabled. However, the shortcut keys of "(De)Select All", "Invert Selection", and so on do work. I've tried rebooting the entire computer and still I have this problem.



Pressed every single side of the mouse.
Click with the other side of the Mouse



Press 
a
 one or twice so that nothing is selected and the image looks dim not bright.  Its a toggle.

Then Click Only



Then use
b
for box select and you should see a difference.

My opinion is that everything is selected in you original question.

You can also press 
W
then select subdivide to have more variation in your selection.

Perhaps you  already know this.