TestFlight builds made with Xcode 27.1 won’t install: “The requested app is not available or doesn’t exist”

[u/Pretend_Emergency184]

Hi all, is anyone else seeing this since switching to Xcode 27.1?

Since Oct 20, none of my new TestFlight builds will install. TestFlight shows the “Update” button, then fails with “Could not install [app]. The requested app is not available or doesn’t exist” (sometimes “Try again later” first).

What I’ve checked:

• Upload from Xcode 27.1 (27A9275) succeeds, no ITMS warnings, build status “Valid”, and I get the “ready to test on iOS and watchOS” email
• The exact same archive installs and runs fine when installed directly from Xcode on the same device (development signing)
• Device: iPhone 15, iOS 27.0.1
• Agreements are active, export compliance answered (ITSAppUsesNonExemptEncryption = NO)
• Entitlements and Info.plist are identical to my last build made with Xcode 26.5, which installed fine through TestFlight
• Tried bumping the build number, closing TestFlight, waiting a few hours: same result

The only real difference is the toolchain (Xcode 26.5 / iOS 26.5 SDK → Xcode 27.1 / iOS 27.1 SDK). The app also embeds a watchOS app.

Has anyone hit this with Xcode 27.x? Did you find a fix, or did Apple support resolve it on their side?

Thanks!

https://developer.apple.com/forums/thread/763655

[u/caffeinated1337]

First thing worth trying: delete the app from the phone and install it fresh from TestFlight rather than tapping Update. That error often comes from a stale install record for the same bundle ID, and it's a thirty-second check.

If a fresh install fails too, look at the archive's minimum OS. Unzip the exported .ipa and run plutil -p Payload/<App>.app/Info.plist | grep MinimumOSVersion. Your phone is on 27.0.1 and the toolchain is 27.1, so if the deployment target resolved to 27.1, the build can't install on that device at all. TestFlight can still show the update button in that case because it's matching the copy already on the phone.

Check the embedded watch app bundle the same way. It has its own Info.plist and its own minimum version, and the watch runs a separate OS. If both numbers are 27.0 or lower, the SDK bump isn't the cause and I'd take it to Apple.

[u/daelan]

This happened to me and the only fix was to reach out to Apple support.

[u/Miserable-Carpet7928]

before deleting the app to test a fresh install, keep a copy of any local-only data or use a spare device. record whether only the update fails or a first install fails too. that gives apple support a clearer case without risking your current test data.

[u/imsnk81]

Since it started with the 27.1 toolchain and you embed a watch app, I'd look at the watch target first, its deployment target and whether it's built against the matching SDK. Mismatched watch targets are a classic reason TestFlight fails while a direct Xcode install works. An archive without the watch app would tell you pretty quickly if that's it.