The "SMS Status; Undeliverable - Violation" is an error that indicates that SMS carriers (AT&T, Verizon, etc.) see the content as spam and block delivery.
To resolve the error, we have included a "reset" that you can click to reset the spam flag. After you reset, you will be able to send a different message.
NOTE: Do not attempt to continue sending the same message. This will continue to trigger spam, even after resetting. Instead, change the wording of your message after you reset in order to send it successfully.