Test Flight: "The invite has already been used"

Question

I'm sending my client a build through Test Flight (via iTunes Connect) and he's receiving this error in Test Flight app when opening link coming from iTunes Connect

Answer 1

This may be caused by a number of reasons.

1. Try to send another invitation to him The easiest way to solve this problem is to send another invitation to the person who tests it. Either register another internal user for testing or get another email via external users.
2. Do not open the link on your computer or iPhone Since TestFlight was taken over by Apple, builds aren't tied to devices anymore, what leads to apple distributing apps by unique links. Each and every link you get an be used only once. If you open this link or install a build through it it becomes unusable.
3. Apple's Mistake There's a minor chance that Apple made a mistake and gave you a used link. This is my last point, as the odds are really small.

In any way, just resend a new link. You can do that by following point 1.

I hope that helps.

Julian

Edit: As the asker himself added as comment, only adding a user won't make the trick. You have to enable Internal Testing for him under users and roles and also turn on internal testing for the app too. The problem was resolved, as the "client" was sharing his link and using it twice, even that doesn't work

Answer 2

Adding the same user again to the testflight account wont work. If you accepted the invitation and the app showed in your Testflight app, that will remain there on all devices(associated with the same Apple Id). If you need to download TestFlight to another device, it can be downloaded from the App Store. Your previously accepted invitations will show up when you download TestFlight on another device.