The Function of DisableViewerAnnotation doesn't work ,which Returns Value 24

Hi Engineer,
I am a C# developer.I got a problem with function of DisableViewerAnnotation . I can confirm that the Switch Button status on the Management Webpage is on . But I always got the return value 24 when I try with function of DisableViewerAnnotation(SDKViewType.SDK_FIRST_VIEW, false/true) in my code . I retrieval the value 24 of SDKError ,that is “Annotation is off”. As the same time the other Function of CanDisableViewerAnnotation returns “true” . Did I miss anything Important?
By the way, In Version 5.5 it works well, But this happened in Version 5.9 later。
Hopping your feedback.