Hi @Entlife, welcome to our forum!
It does sound that the Guest mode has been activated in the device and this mode does not have permission to access the Messaging application.
If you drag down the notification field twice with one finger or put two fingers at the top of the screen and drag them downwards you will see a blue icon that is showing the head and shoulders of a person, tap this icon and and tap on the most left icon (Owner). You can also change this if you go to Settings > Users > and choose the main account (your name or "Owner").
Let me know if that helps! 
0online
1897524posts