I seem to have the exact issue as above mentioned. In my case, I play audio in the background also as a notification, and use animations as well. What I was able to determine until now: it only happens when the app is in the background it has to do with audio what I still don't know: dose it have anything to do with animations, as it is mentioned in the error itself? dose the app crash immediately as the error occurs, or the moment the app returns in the foreground.

So I will post an answer to this issue, as it may help someone in the future who has a similar issue. As it turns out, the problem was indeed with the animations. In most parts of my code I used the following instance method: func animation(_ animation: Animation?) -> some View Which btw. apparently will be deprecated in iOS 15. Source: Apple documentation The problem was that every time the view was reloaded all the views got animated regardless if they should or not. My personal guess is that this was causing some concurrency issues in the background. Anyways, the solution seams to be this func animation<V>(_ animation: Animation?, value: V) -> some View where V : Equatable Where value is: A value to monitor for changes. Using this, if you configure the view properly, even when running in the background, views will get animated when the monitored value has changed. I hope this will help someone. This definitely solved my problem!