Blocking Active Message.

When trying to set up the app for the first time, I receive┬áthe error message “blocking active message.”

This issue appears to be due to a feature implemented by the TMobile network.

It is a free T-Mobile service that allows you to block messages to and from your phone, to help you avoid unwanted messages.

https://support.t-mobile.com/docs/DOC-1712

You can adjust the setting with T-Mobile and this should resolve the issue.