Troubleshooting

“No signing certificate found”

• Open Keychain Access which is located in the Utilities folder inside Applications.
• Select ‘Show Expired Certificates’ in the View menu.
• Delete the expired version of the Apple Worldwide Developer Relations Certificate Authority Intermediate certificate from both the login and system keychains.
• Download and install the renewed Apple WWDR certificate.

“This app contains an app extension with an illegal bundle identifier”

Install the latest version of iOS App Signer.