Middle Row of Keyboard Stopped Working

Ouch! not good ;-{

If you haven't worked on these systems before you should think about bring it into an Apple Store and letting them replace the upper case. Hopefully, its nothing more than the keyboard that got hit.

If you are up to giving it a try here is the IFIXIT guide: MacBook Air 13" Early 2014 Upper Case Replacement. Now with the winter coming on make sure you follow good ESD practices and use an antistatic mat and wrist strap as you'll need to take the logic board fully out.

Some people do manage to take the keyboard fully out after they remove the uppercase to try to clean it. Frankly, it's a lot of work and often the results are not as good as just replacing the keyboard which you could do here as well if you've done it a few times. Still a lot of work which is why for a DIY project I recommend just replacing the uppercase assembly.