I will do it, thanks a lot! @eskimo. Btw: I feel there is a security concern if a process is muted by path, let's say if I muted a trusted process by path, however, the process might be replaced by a totally different one with the same path, then the events of the "new" one also are muted, right?

could be a system bug? since looks like the infinite "close" send from _NSThemeCloseWidget, no stack of the App is involved...

Thanks, OOPer. I remove the observer in the notification block. Btw: I just saw this crash once and there have call stacks of the system only, also I am not sure when there is -[NSWindow _finishClosingWindow] when launching my App.

Thanks, OOPer. I just do [[NSNotificationCenter defaultCenter] removeObserver:self] inside the block. There are only call stacks of system libraries in the crash log, not my own app stack involved. I only see this crash once. Btw: why I can see NSWindow _finishClosingWindow when launching my App?