I have been developing an app for a little while now. I have been building it without any entitlements/sandboxing, but I decided to try to turn on sandboxing, and I noticed the exact same issue. The video player says “This video is playing in picture in picture”, and I can hear the audio, but the video doesn’t show up. Additionally, there is an error that shows up in the video playback menu bar item. I also see this error in the console which I suspect is related, but not positive: 0x114041e90 - ProcessAssertion::acquireSync Failed to acquire RBS assertion 'WebKit Media Playback' for process with PID=51324, error: Error Domain=RBSServiceErrorDomain Code=1 "(originator doesn't have entitlement com.apple.runningboard.assertions.webkit AND originator doesn't have entitlement com.apple.multitasking.systemappassertions)" UserInfo={NSLocalizedFailureReason=(originator doesn't have entitlement com.apple.runningboard.assertions.webkit AND originator doesn't have entitlement com.apple.multitasking.systemappassertions)} I tried adding these entitlements to my app, but that causes it to crash on startup. Supposedly they are reserved for Apple only. I am on macOS sonoma 14.5 (23F79) on Apple Silicon M1 Just wanted to add that adding com.apple.PIPAgent to com.apple.security.temporary-exception.mach-lookup.global-name entitlement as referenced in this thread fixed it for me: https://developer.apple.com/forums/thread/756472