You installed everything, but Facebook Lite crashes immediately. Here is the fixed diagnostic guide:

| Error | Solution (The Fix) | | :--- | :--- | | "Untrusted Developer" | Go to Settings > General > Device Management. Find the profile and tap Trust. | | App opens then closes (Crash) | The certificate was revoked. Delete the app, turn on Airplane Mode, reinstall via Scarlet/Sideloadly, then turn WiFi back on. | | "Invalid IPA" | The file is corrupted. You need a freshly dumped IPA. We recommend version 388.0 or 393.0. Avoid auto-updaters. | | Login Loop | Uninstall the main Facebook app first. Facebook Lite conflicts with the main app’s token. | | "Unable to Download" on iOS 14 | You have low storage. The device reserves 1GB for verification. Delete old videos and try again. |

Fix: Your Apple ID reached the 3-app limit. Use a different Apple ID or revoke old certificates via AltStore → Settings → Revoke Certificates.

To install these IPAs without a computer, users are often directed to install a "Profile" (Mobile Device Management). Once installed, the MDM profile gives the app creator remote control over your device, including the ability to: