I don't know if there's a KB yet, but I have pinned down the issue that is causing this problem. The weirdly formatted and invalid number error happens when you try to send a message to someone without any contact data. Lets say you're texting your best friend Tony. New Message > *Type in Tony* > Hit enter (That's the crucial step as if you don't select Tony's number, the message won't go anywhere) Message > Hey bro, want to grab some dinner? *Send* +1 (1) (216) 116-11 Error! Try it out:Type in a random first name not in your contacts. Hit enter and send a message. You'll get the error. Now do it again with a friend you know has a good number, don't select their name, just hit enter. Send a message.You'll get the error. I can provide demo videos if needed, but hopefully that helps with troubleshooting the issue.

At&t +1 (1) (216) 116-11 - Solution for Messaging

I don't know if there's a KB yet, but I have pinned down the issue that is causing this problem.

The weirdly formatted and invalid number error happens when you try to send a message to someone without any contact data.

Lets say you're texting your best friend Tony.

New Message > *Type in Tony* > Hit enter

(That's the crucial step as if you don't select Tony's number, the message won't go anywhere)

Message > Hey bro, want to grab some dinner?

*Send*

+1 (1) (216) 116-11 Error!

Try it out:

Type in a random first name not in your contacts.

Hit enter and send a message.

You'll get the error.

Now do it again with a friend you know has a good number, don't select their name, just hit enter.

Send a message.

You'll get the error.

I can provide demo videos if needed, but hopefully that helps with troubleshooting the issue.

Posted on Nov 27, 2015 11:28 AM