Can't send texts - Cell Phones

I can't send or receive text messages (SMS/MMS)

1. Check your default messaging app. On Android Messages. ...
2. Update your Google Fi app. In general, we recommend keeping all of your phone's apps up to date. ...
3. Make sure you're using a valid phone number with the correct format. ...
4. Check if your contact is using an iPhone. ...
5. Restart your phone. ...
6. Talk to a Google Fi agent.

1. Go to Settings > Apps, find your stock SMS app (the one that came pre-installed on your phone).
2. Tap it, and make sure its not disabled. If it is, enable it.
3. Now launch the SMS app, and look for the SMSC setting. ...
4. Enter your SMSC, save it, and try to send a text message.