I confirmed that [MXMetricManager addSubscriber] is called twice - it's invoked from another internal swift framework. Should there be only one subscriber? We had to remove a subscriber and release a version to stop the influx of crashes. I submitted a bug using Feedback Assistant: https://feedbackassistant.apple.com/feedback/11525011 I see that it says "Potential fix identified - For a future OS update"

Seeing this here as we're getting alerted due to a spike in crashes due to this issue since the public release of iOS 16. Full crash report attached. metrickit.crash