Most install errors for test builds come down to one thing: the build isn't signed for that iPhone. Here's how to find the real cause.
"Unable to Install" or "Please try again later"
- The iPhone isn't in the provisioning profile. This is the most common cause. Check the iPhone's UDID was registered before the build was signed. With BuildFerry, make sure the request was approved.
- Not enough storage. Free some space and try again.
- An App Store copy is installed. If the App Store version has the same bundle ID, delete it first.
"This app cannot be installed because its integrity could not be verified"
iOS checked the signature and something didn't match:
- The build was signed with a profile that doesn't include this iPhone.
- The distribution certificate was revoked or expired.
- The .ipa was changed after signing.
Re-sign the build for the device, or with BuildFerry, check that the iPhone is approved and install again.
The Install button does nothing
The link was opened inside another app, such as Gmail, Slack or Instagram. In-app browsers can't install apps. Copy the link and open it in Safari.
The app installs, then won't open
- The profile or certificate expired. Ad hoc profiles last a year. Sign a new build.
- Developer Mode. If iOS says Developer Mode is required, the build was signed for development. Turn it on under Settings, Privacy & Security, Developer Mode, or use a distribution build instead.
- "Untrusted Enterprise Developer" only appears for enterprise builds. Trust the developer under Settings, General, VPN & Device Management.
"This app requires a newer version of iOS"
The app's minimum iOS version is higher than the iPhone's. Update iOS, or lower the deployment target and rebuild.
No more device slots
If a new iPhone can't be registered, your team has used its 100 devices for the year. Slots only come back at renewal.
Questions
Why does my iPhone say Unable to Install?
Usually because the build isn't signed for that iPhone: its UDID wasn't in the provisioning profile when the app was signed. Low storage or an App Store copy with the same bundle ID can also cause it.
What does "integrity could not be verified" mean?
iOS couldn't confirm the app's signature for this device. The profile may not include the iPhone, the certificate may be revoked, or the file changed after signing.
Why does the Install button do nothing?
The link is probably open inside another app. Open it in Safari, which is the only browser that can install apps over the air.