Need to send a message from AppDelegate to view model in PCL . Please HELP!!!

I have to send a message to the view model in PCL to log an exception when I catch unhandled exception in Appdelegate. I am not
able to send messages to the view model.. Running into compilation errors

Here is code in the AppDelegate for IOS :

    public override bool FinishedLaunching(UIApplication app, NSDictionary options)
            {
                AppDomain.CurrentDomain.UnhandledException += CurrentDomainOnUnhandledException;
                TaskScheduler.UnobservedTaskException += TaskSchedulerOnUnobservedTaskException; 

                Forms.Init();
           }

    private static void TaskSchedulerOnUnobservedTaskException(object sender, UnobservedTaskExceptionEventArgs unobservedTaskExceptionEventArgs)
            {
                var exception = new Exception("TaskSchedulerOnUnobservedTaskException", unobservedTaskExceptionEventArgs.Exception);

    // sending the message
                MessagingCenter.Send( ExceptionLoggerViewModel, MessagingCenterMessages.ExceptionLoggerActivated,               unobservedTaskExceptionEventArgs.Exception);
            }

Here is the code in PCL in the view model where I subscribe for the message:

public ExceptionLoggerViewModel(ICache cache)
            {
                _cache = cache;

                MessagingCenter.Subscribe<ExceptionLoggerViewModel, Exception>(this, MessagingCenterMessages.ExceptionLoggerActivated,
                      async (sender, exception) => await ExceptionLoggerViewModel_logException(exception));

            }

I get an compilation error :
Error 13 'RA.Mobile.HEROGov.PCL.ViewModels.Pages.ExceptionLoggerViewModel' is a 'type' but is used like a 'variable' C:\tfs\VIRTUALRA8271L.REL.RA.Mobile.HEROGov\iOS\AppDelegate.cs 96 35 RA.Mobile.HEROGov.iOS

Any help is appreciated. Thanks