I am using the production version of XCode and up until today I was able to send Testflight invites out. But now I get the following message.
This build is using a beta version of Xcode and can’t be submitted. Make sure you’re using the latest version of Xcode or the latest seed release found in the TestFlight release notes.
I triple checked. I'm using 9.2 (9C40b) to do the build.
Rob