Leo downloaded the installer from a mirror site (the official one was “temporarily slow”). He double-clicked the .exe file. The progress bar filled to 98%—then stopped.
Connect your device and drag the IPA file into the Sideloadly window. 3utools installation package validation failed
: If you are trying to install a custom app, use the "IPA Signature" tool within the 3uTools Toolbox tab. Sign the file with your Apple ID first, then attempt to install the signed version. Leo downloaded the installer from a mirror site
He ran the setup again.
: Security software often flags jailbreak or sideloading tools as malicious, intercepting the package before it can finish. Temporarily disable Real-time protection in Windows Security and try again. 3utools installation package validation failed