App crashes during WebView initialization in Lockdown Mode

[omersayshi]

Prerequisites

• I have verified this issue is specific to YouTubePlayerKit and not a limitation or bug of the YouTube Player iFrame API.

What happened?

During the WebView initialization YouTubePlayerWebView.init at YouTubePlayerWebView.swift LINE 41. WebKit checks for the web policies API::WebsitePolicies::WebsitePolicies and app consistently crashes at this level WebKit::WebPagePreferencesLockdownModeObserver::WebPagePreferencesLockdownModeObserver -> WebKit::lockdownModeObservers -> WebKit::lockdownModeObservers at that line the app crashes.

What are the steps to reproduce?

It was a user reported issue. I was not able to personally reproduce the bug, I suspect it has something to do with Apple's newly introduced lockdown mode. I verified that the player works on my device with lockdown mode enabled.

What is the expected behavior?

App doesn't crash.

[SvenTiigi]

Hi @omersayshi,

Thanks for your bug report.
Certainly I'm not able to reproduce this crash.
I have tested it with LockDown Mode enabled on an iPhone 15 Pro with iOS 18.3.1 and on an iPhone XS with iOS 17.0.1.

Based on the crash information you provided, I suspect that there is an internal bug in the WebKit Framework. This bug may be triggered by various factors, as the crash involves an internal WebKit component "lockdownModeObservers".

It would be best to gather more information about the crash such as the specific device, OS version, parameters and configuration of the YouTubePlayer as well as debug logs.