Hello Guys.
First, I'm not on a KitKat, but i'm experiencing the same error after installing an app from google play store.
The application in question is the "Message Classic" that claimed to had been ported from the Android 4.4 (Kitkat) to other devices.
In my case, i uninstalled this application and the annoying popup message stopped appearing on the screen.
In Kitkat, this application is probably the stock messaging (SMS & MMS) app,so if you can't uninstall it may still be possible to disable it and solve the problem.
A workaround could be to use Hangouts application to handle your messages instead.
But as i said, i'm not on a KitKat so is a long shot but i guess it's worth a try.
Good luck & let me know if this solve your problem.