SMS Hanging in Windows Client

I have an AT&T S4 and am trying to send an SMS from the new Windows client. I can do this with the Web client, but not the native Windows client. Any thoughts or troubleshooting? Message appears as a new bubble, but the activity indicator just keeps spinning.

I'm having exactly the same problem with my S5

When to send SMS from the application on my computer, it does not come confirmation of delivery, although the SMS is delivered. The problem is not large, but want to be sure that the message is delivered to the recipient.
The screenshot shows three upper sms transferred from the program on the computer, and the last SMS directly from the interface of the smartphone