Sometimes, leftover certificates from previous sideloading attempts block new installations. Clearing them refreshes the connection. Open Cydia Impactor and connect your iOS device via USB. Click on the menu option at the top of the interface. Select Revoke Certificates from the dropdown menu.

If you are trying to update an app or reinstall a revoked app, the older version can cause a conflict. Disconnect your iOS device from your computer. Locate the app icon on your home screen. Tap and hold the icon, then select . Restart your iOS device to clear the temporary cache. Reconnect the device and try sideloading again. 2. Revoke Existing Certificates

This is a very popular and safe tool to install apps on iOS.

Some users report success by disabling Mail’s authentication integration on macOS. This is a niche fix but worth trying if you are on an older Mac.

Install AltServer on your PC/Mac, connect your phone via lightning/USB-C, select "Install AltStore," and use the on-device AltStore app to sign your IPAs. Alternative 2: Sideloadly

: A version of the app you are trying to install already exists on the device.