An error is reported when playing h5 audio or video elements in wkwebview: Error acquiring assertion: Error Domain=RBSAssertionErrorDomain Code=3 "Required client entitlement is missing" UserInfo={RBSAssertionAttribute=RBSDomainAttribute| domain:"com.apple.webkit" name:"MediaPlayback" sourceEnvironment:"(null)", NSLocalizedFailureReason=Required client entitlement is missing} Then the performance of the webview will become very poor. There is an audio element and a button button in my HTML file. Click the button to play audio. body button onclick="handleClick()"PLAY/button audio id="audio" src="https://ac-dev.oss-cn-hangzhou.aliyuncs.com/test-2022-music.mp3"/audio script function handleClick() { document.getElementById("audio").play(); } /script /body Create a wkwebview to load the html file in my demo APP. class ViewController: UIViewController , WKUIDelegate{ var webView: WKWebView! override func loadView() { let config = WKWebViewConfiguration() config.preferences.javaScriptEnabled = true config.allowsInlineMediaPlayback = true webView = WKWebView(frame: .zero, configuration: config) //.zero webView.uiDelegate = self view = webView } override func viewDidLoad() { super.viewDidLoad() let myURL = URL(string: "https://ac-dev.oss-cn-hangzhou.aliyuncs.com/test-2022-py.html") let myRequest = URLRequest(url: myURL!) webView.load(myRequest) } } Click the button in the HTML to play the audio, and you can see the error report on the xcode. iPadN[2133:855729] [assertion] Error acquiring assertion: Error Domain=RBSAssertionErrorDomain Code=3 "Required client entitlement is missing" UserInfo={RBSAssertionAttribute=RBSDomainAttribute| domain:"com.apple.webkit" name:"MediaPlayback" sourceEnvironment:"(null)", NSLocalizedFailureReason=Required client entitlement is missing} To sum up, this error will appear when playing audio or video in HTML. Then the app performance will drop a lot, and the interactive response will be very slow.