Don't have exact PDF file that caused a problem, but stack-trace seems specific enough to address the problem.
Dictionary`2[TKey,TValue].get_Item (TKey key)
PdfMainObjectCollection.GetObject (Syncfusion.Pdf.Primitives.PdfReference reference)
PdfReferenceHolder.ObtainObject ()
PdfReferenceHolder.get_Object ()
PdfCrossTable.GetObject (Syncfusion.Pdf.Primitives.IPdfPrimitive pointer)
PdfLoadedPageCollection.get_Count ()
PdfLoadedPageCollection.GetParent (System.Int32 index, System.Int32& localIndex, System.Boolean zeroValid, System.Boolean enableFastFetching)
PdfLoadedPageCollection.GetPage (System.Int32 index)
PdfLoadedPageCollection.get_Item (System.Int32 index)
LinearLayoutEx.InitializeLayout ()
HorizontalScrollViewEx.Initializelayout ()
ScrollViewEx.InitializeLayout ()
ScrollViewEx.LoadDocument (System.IO.Stream inputStream)
SfPdfDocumentViewRenderer.OnElementPropertyChanged (System.Object sender, System.ComponentModel.PropertyChangedEventArgs e)
(wrapper delegate-invoke) <Module>.invoke_void_object_PropertyChangedEventArgs(object,System.ComponentModel.PropertyChangedEventArgs)
BindableObject.OnPropertyChanged (System.String propertyName)
Element.OnPropertyChanged (System.String propertyName)
BindableObject.SetValueActual (Xamarin.Forms.BindableProperty property, Xamarin.Forms.BindableObject+BindablePropertyContext context, System.Object value, System.Boolean currentlyApplying, Xamarin.Forms.Internals.SetValueFlags attributes, System.Boolean silent)
BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.Internals.SetValueFlags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes)
BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value, System.Boolean fromStyle, System.Boolean checkAccess)
BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value)
DocumentViewHelper.set_InputFileStream (System.IO.Stream value)
SfPdfViewer.OnPdfViewerPropertyChanged (System.String propertyName)
SfPdfViewer.OnInputFileStreamChanged (Xamarin.Forms.BindableObject bindable, System.Object oldValue, System.Object newValue)
BindableObject.SetValueActual (Xamarin.Forms.BindableProperty property, Xamarin.Forms.BindableObject+BindablePropertyContext context, System.Object value, System.Boolean currentlyApplying, Xamarin.Forms.Internals.SetValueFlags attributes, System.Boolean silent)
BindableObject.