After uninstalling iBooks, I can't sign in to iTunes any more I am currently using El Capitan.

Every time I uninstalled iBooks so I could manage my books with iTunes, I found I simply couldn't sign in to iTunes any more. That means I click the 'sign in' button but no sign-in window pops up. I can't purchase or re-download any of my music or books. 

And reinstalling iBooks fixes it all.

Is there a way I can manage my books with iTunes and can still sign into my account?
Uninstall iTunes 12.3.x 
then install iTunes 12.2.x. 


Seems as if 12.3 must have iBooks not so with 12.2.2.