#nsnotificationcenter

Observer <object> was not registered as an observer – duplicate removeObserver call

When developing with Foundation’s NSNotificationCenter, developers often need to clean up observers in deinit or cleanup routines. Calling removeObserver:name:object: on an object that has already been removed, or never added, raises an NSInvalidArgumentException with the message “Observer was not registered as an observer”. The decision point is whether to

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