Xcode 8.3. Trying to upload my app for TestFlight. As far as I can tell, I have everything lined up: My iOS development certificate, my app ID appears to be correct, I have a distribution profile that I have downloaded and I think is installed, (although this may be a problem, when I double click on it, it opens the beta version of Xcode 9, so I'm not sure if it's really seen in my 8 version).
On Itunes Connect I created my app, it's listed as Prepare for submission, and the bundle Id is the same as what is listed in Xcode.
So what is the piece I'm missing, what's with the message?