SMS problem on moto g after updating android 4.4.4
On Moto G the stock Messaging app is an integral part of the system, and should not be disabled even if you install other SMS apps.  If you manage to disable it, other 3rd-party SMS apps (like Textra SMS in your case) will start crashing again.

Instead, you can disable the notifications inside the Messaging app by going to menu -> Settings, and un-checking the "Notifications" option: