How to Fix Scarlet Certificate Errors

This appears the first time you open Scarlet or a freshly sideloaded app. It isn’t a sign of a problem — instead, it’s iOS’s standard gatekeeping for any app that didn’t come from the App Store. Go to Settings → General → VPN & Device Management, tap the developer profile listed there, and tap Trust (some iOS versions show a second confirmation step labeled Verify App after that). The app should open normally afterward.

Before anything certificate-related, rule out the simple causes: free up storage if your device is close to full (a mod install needs headroom beyond the file size itself), and confirm your iOS version isn’t older than what Scarlet currently supports — an outdated iOS version is a common, easy-to-miss cause of a silent install failure. Restarting the device also clears up a surprising number of one-off install glitches.

This specific message means Apple has revoked the certificate behind the app, not that the file is corrupted or unsafe. It’s the most common failure mode for enterprise-signed tools like Scarlet, since Apple actively hunts down and revokes these certificates — sometimes weeks apart, sometimes sooner, with no announced schedule. The fix is simply to reinstall through Scarlet once it has a fresh certificate again; there’s no setting on your end that prevents this from recurring.

Some networks — school, work, or public Wi-Fi in particular — block the certificate-verification traffic an enterprise-signed install depends on, even when the download itself completes normally. If an install or trust step hangs specifically on one network, switch to mobile data or a different Wi-Fi network before troubleshooting anything else.

Enterprise-signed tools are the least stable category of sideloading method — Scarlet included — precisely because Apple targets the certificates they depend on. If Scarlet’s own install link stops working, or the same certificate errors keep resurfacing no matter how many times you reinstall, that’s a sign to look at a different category of sideloading tool rather than keep retrying the same one. Tools that sign apps with your own Apple ID (like AltStore or Sideloadly) or your own certificate (like Feather) don’t disappear the same way, at the cost of a bit more setup.

If none of the fixes above stick, compare the alternatives to Scarlet and consider switching tools instead of continuing to fight the same certificate errors.

Why did my sideloaded mod suddenly stop opening after working fine for weeks?

Apple almost certainly revoked the enterprise certificate that signed the app. This isn’t tied to anything you did, and it isn’t specific to one mod — every app sideloaded the same way stops at once when Apple revokes the certificate behind it.

Is there a way to stop the certificate from being revoked?

Not with an enterprise-signed tool like Scarlet on a standard, non-jailbroken iPhone — revocation is Apple’s decision, not something you can block from your device. Certificate-based tools that use your own Apple ID or your own certificate are more predictable (typically a known 7-day cycle rather than a surprise revoke), but they still expire on their own schedule.

Do I need to redownload the mod’s IPA file, or just reinstall through Scarlet?

Just reinstall through Scarlet. The mod’s IPA file hasn’t changed — only the signature covering it has expired — so re-signing the same file is enough unless the mod actually ships a new version.

Is this a problem with the mod’s file, or with Scarlet?

It’s a Scarlet certificate error, not a problem with the mod file. This site scans every IPA with ClamAV before publication regardless of platform, and that scan result doesn’t change when a sideloading certificate expires — the two are unrelated failure points.