KitKat update has made Google Play and Gmail inaccessable The update to KitKat on my phone was done automatically, and since then I have been unable to access google play, or sign into gmail. I've gotten no notifications or e-mails since Nov. 23rd. I'm told I can't sign into Gmail, but when I'm prompted to try, I can't even get to the screen.
Yeah first please answer the question that which device you are using and did you get an official update from your manufacturer or did you manually install a custom ROM?
(Although by your post it seems an official manufacturer update but please confirm...)

IF:
1.Official update , then you can just do that update all over again and this time try it through PC software(if you had previously done an Over the Air update). Or finally contact your manufacturer's customer care or go to service center.

2.Custom ROM , then it may be problem with the ROM or kernel . Reach the developer for that. Or you can even replace the Google Apps. Just find an appropriate .zip coinciding with your Android version.

Hope this helps or ask again with doubts. :)