Hi Toby,
This doesn't necessarily mean that there's an error. In order to be proactive, we delivered this in-app announcement to those that this might affect. You should be able to handle this without Support's help by taking a look at the "Set the outbound calling address" section of the "Create an external trunk" Resource Center article.
Here's the link:
https://help.mypurecloud.com/articles/configure-an-external-trunk/
I hope this helps.