Why did my Command + V (to paste) suddenly stop working? Maybe I should be weary every time I do one of these shady Apple updates on my 3-year old Mac running 10.11.5.

Suddenly, the shortcut to paste, ⌘ Command V, stopped working for me. But all other shortcuts using the ⌘ Command key still work, such as Copy, Cut, Find, Minimize, etc. Paste still works if I do it manually with the mouse by going up to Edit and clicking Paste.  

Even when I log into another user, same problem.  And when I am in Recovery Mode, same problem.  And I don't think I have any recent add-ons, as far as I can tell.

I restarted several times and reset my Keyboard in System Preferences. I even tried a few random code stuff in Monitor that I found on other forums. Nothing has worked.
I had the same issue in Mac Excel 2011 I am still using. 

-Right click on the Paste icon in toolbar, choose Properties...
-Next screen, click Keyboard... on right hand side
-In "Press new shortcut key", add command+v.

That worked, even though command+v was already in list of current keyboard keys for Paste function. Hope this helps