“Unable to install” & “integrity could not be verified”: how to fix sideload errors

Almost every sideloading failure falls into one of five buckets. Find your message below.

“Unable to Install — please try again later”

• VPN or ad-block DNS active — the #1 cause. iOS must reach Apple's servers to validate the profile. Turn off the VPN (including router-level VPNs — use 4G/5G for the install) and any DNS like AdGuard/NextDNS. Details: VPN & DNS issues.
• Low storage — keep at least 1 GB free.
• Bundle ID collision — an app with the same identifier is already installed from another source. Change the bundle identifier in the signer, or delete the old app.
• Interrupted download — retry from the signer app; OTA installs time out on slow connections.

“This app cannot be installed because its integrity could not be verified”

• Certificate revoked — the most common reason. What to do.
• UDID mismatch — the certificate was generated for a different device. Check your UDID against the one on your order.
• Profile expired — certificates are valid up to one year; see validity.
• Mismatched files — the .p12 and .mobileprovision come from different certificates. Re-download the zip from your order page.

“Untrusted Developer”

Not an error — trust it once in Settings → General → VPN & Device Management. Guide: trusting a developer app.

Install stuck at 100 % / icon stays dark

1. Wait 60 seconds — iOS verifies large apps after download.
2. Lock and unlock the device, or restart it.
3. Delete the dark icon, disable VPN/DNS, install again.

App installs but crashes on open

Revoked certificate (see above), or the app itself needs entitlements your certificate doesn't provide (rare; try another package, e.g. Cert Pro). Some apps also refuse to run on jailbroken or bypassed devices.