I am getting message "TestFlight is Currently is Currently Unavailable. Try again later" when trying to install from TestFlight app. My outside testers get a message "[App Name] beta has expired" when trying to run the app. When trying to renew from TestFlight they get "TestFlight is currently unavailable. Try again later." I've been trying again later all day and just wanted to see if anyone else is experiencing this.
TestFlight is Currently Unavailable Message
20.9k Views Asked by Paul4468 AtThere are 12 best solutions below

Another possible reason for this message:
You accidentally removed the affected user from the TestFlight external testers group.
Adding him again would fix the issue.

Actually just waiting solved the problem.
I had to wait around 16 hours and then it worked normally, without doing anything particular.
Sometimes the error message is just what it is, no need to panic !
Ahh devs ;)

Make sure TestFlight can use Mobile Data if working without Wi-Fi. Otherwise it fails with this generic error.

I had this same issue when using my personal email for beta testing my app, then using my apple ID email for internal testing.
I solved this issue by removing my personal email from all testing tracks, then deleting the TestFlight app and downloading it again. I now only use the one email (my Apple ID) for all testing.

Problems with certificates have been identified in several answers as the cause to this message. However, there's another possible (yet stupid) cause that leads to this situation.
You may see this error if your device's date/time is not set correctly. So make sure you set the correct date or "Set Automatically" is enabled under Settings > Date & Time.
I spent 2 days "trying again later" until I realized this.

I was ultimately able to fix this message by uninstalling and reinstalling the TestFlight app from scratch. Worth a try if the other answers don't fix your problem.

I had to go to https://developer.apple.com and accept a new version of Apple's Developer Agreement
I had this same error.
Discovered that the company certificate was expired, and therefor all provisioning profiles as well.
1. Renew the company certificate (download, install on your computer)
2. Renew the provisioning profiles (edit, select new valid certificate, generate, download and install in xcode)
3. Repost the app to iTunes connect
problem solved :)
If you're new to Xcode, be sure to note the difference between a CERTIFICATE (first large red arrow below) and then a PROVISIONING-PROFILE (second large red arrow below). Basically provisioning-profiles are made using a certificate. So first make a new certificate, and then set a provisioning profile to use that certificate.
First, certificate...
Then, provisioning profile...
In the second image, click on the "Distribution" provisioning profile (the one with the purple arrow.) Then click to edit it, and you will then see the third image below. Note that somewhat annoyingly, the DATE is the only way really to distinguish your corporate certificates, when, you have more than one. (Ultimately you can, generally, just throw away the OLDER one, but it's clearer if you leave it so that you can clearly see how you select one or the other, as in this third image.)
Editing a provisioning profile...
A minor point is that you'll have to make a new build (so, increase the build number in Xcode, then archive, and then send up that new one) because you'll get a "redundant build" warning if you fix the cert/profile (i.e., as described in this answer) and re-submit.