There's another thread with many people having the same problem, it's not just us: https://developer.apple.com/forums/thread/127678

Same here -- trying all day to fix it.. glad it's not just me! Here are the errors I'm getting: App Store Connect Operation Error Your app contains non-public API usage. Please review the errors, correct them, and resubmit your application. App Store Connect Operation Error The app references non-public selectors in Payload: applicationNameForUserAgent, initWithFrame:configuration:, isMainFrame, navigationDelegate, navigationType, setNavigationDelegate:, setProcessPool:, targetFrame, userContentController I've removed any suspect plugins down to the core plugins: Camera, Device, File, and Geolocation, which are all established plugins, but no matter what, the exact same errors above persist every time I submit the app from XCode for validation. And all versions and tools are up to date. Apple -- can I have a day's pay back that I've wasted on this?

I've been having essentially the exact same error all day today trying to validate a Cordova app that worked fine in the past. Here are the errors I'm getting: App Store Connect Operation Error Your app contains non-public API usage. Please review the errors, correct them, and resubmit your application. App Store Connect Operation Error The app references non-public selectors in Payload: applicationNameForUserAgent, initWithFrame:configuration:, isMainFrame, navigationDelegate, navigationType, setNavigationDelegate:, setProcessPool:, targetFrame, userContentController I've removed any suspect plugins down to the core plugins: Camera, Device, File, and Geolocation, which are all established plugins, but no matter what, the exact same errors above persist every time I submit the app from XCode for validation. And all versions and tools are up to date. If this is just a bug on Apple's side, I'll scream, as I've spent all day battling this error and can't find any way to fix it.