Was either of you able to get through to someone who can assist with your account?
Perhaps if you could share more details about the specific error message that's appearing when you attempt to send out a text message, other members here who utilize SmartLine might be able to share some insight on how to work out the issue. Otherwise, I would suggest continuing to reach out to our live support so they can better assist you with the affected account.
For immediate assistance please contact our US based 24/7 customer care team at 480-463-8715. You can also private message me (click on my name) and provide me your SmartLine # and the number you're trying to text.
If it's not a setup issue, then it could be one of the following reasons:
1) You're trying to send a message to a non-text enabled number such as a landline
2) You're trying to send a message to an non-US number. We don't support international texting yet