Tifu and messed up the interface


I deleted a few packages, and one of them I did not recognize (stupid me) and I was in a hurry to leave so I did not see what it was called. Anyway, now when I open a new document it opens in a new tab BEHIND the tab that I am currently using that has the focus whereas before when I opened a new document it would open in a new tab AND that new tab would steal the focus… Any idea how I can restore the old functionality so the new tabs will get the focus again?