SMS disabled on Nexus tablets (KitKat)
The Android 4.4 KitKat update for Nexus tablets disables sms functionality. If you use sms on your Nexus tablet (Nexus 7 2012 3G, Nexus 7 2013 LTE), please be aware of this before updating to Android 4.4 KitKat.
It seems that with Android 4.4 KitKat on Nexus tablets, Google has disabled or hidden the Android "Default sms app" setting. Whether this is accidental or intentional is unknown, however, the effect is the same.
Without the ability to choose a "Default sms app", sms apps won't be able to properly operate.
If you wish to use sms on a Nexus tablet, the quickest solution is not to upgrade to Android 4.4 KitKat.
Otherwise if you want to use Android 4.4 KitKat, you'll have to flash a modified rom or make some system level changes yourself.
Further information can be found at the following links: