SuspensionManager Error when application has more than 1 page in windows 8 XAML/C# app -

i'm writing windows 8 xaml/c# app , have little problem session manager.

within app.xaml.cs onsuspending method looks this:

    private async void onsuspending(object sender, suspendingeventargs e)     {         var deferral = e.suspendingoperation.getdeferral();         //todo: save application state , stop background activity         await suspensionmanager.saveasync();         deferral.complete();     } 

i have registed rootframe suspensionmanager in onlaunched method in app.xaml.cs:

suspensionmanager.registerframe(rootframe, "appframe"); 

so, in first page of app have overriden savestate method. looks this:

    protected override void savestate(dictionary<string, object> pagestate)     {         save(true);          base.savestate(pagestate);     } 

when application suspended method called , works fine.

i have 2nd page savestate method same first (so above).

when navigate 2nd page 1st page , suspend application neither of savestate methods called , application crashes following error:

suspensionmanager failed: unspecified error

brilliant!! not information there!!

so, need different suspensionmanager multiple pages?

thanks in advance

suspensionmanager manager works multiple pages - no issues. given little context, suggest following:

1. have made changes common files auto-generated when creating vs project using grid app template? if yes - try creating fresh project.
2. are passing parameter non-serializable in frame.navigate call? unlikely since in case - can see in output window - winrt information: getnavigationstate doesn't support serialization of parameter type passed frame.navigate.