I'm sometimes getting a null reference exception when calling pdfViewerControl.SaveDocument(). When I exit of the pdf view, I want to save any mark-ups that I've added. So, in the button handler I make a call to pdfViewerControl.SaveDocument(). It seems I'm only having the issue on Android. Sometimes, it works fine, and other times I get a System.NullReferenceException with a source of "SyncFusion.Pdf.Portable."
at Syncfusion.Pdf.Primitives.PdfReferenceHolder.Save (Syncfusion.Pdf.IO.IPdfWriter writer) [0x00021] in <96ea103c151d4af3b40ad4e62cdd8e90>:0
at Syncfusion.Pdf.Primitives.PdfDictionary.SaveItems (Syncfusion.Pdf.IO.IPdfWriter writer) [0x00286] in <96ea103c151d4af3b40ad4e62cdd8e90>:0
at Syncfusion.Pdf.Primitives.PdfDictionary.Save (Syncfusion.Pdf.IO.IPdfWriter writer, System.Boolean bRaiseEvent) [0x00047] in <96ea103c151d4af3b40ad4e62cdd8e90>:0
at Syncfusion.Pdf.Primitives.PdfStream.Save (Syncfusion.Pdf.IO.IPdfWriter writer) [0x001c8] in <96ea103c151d4af3b40ad4e62cdd8e90>:0
at Syncfusion.Pdf.IO.PdfCrossTable.DoSaveObject (Syncfusion.Pdf.Primitives.IPdfPrimitive obj, Syncfusion.Pdf.Primitives.PdfReference reference, Syncfusion.Pdf.IO.PdfWriter writer) [0x000ae] in <96ea103c151d4af3b40ad4e62cdd8e90>:0
at Syncfusion.Pdf.IO.PdfCrossTable.SaveIndirectObject (Syncfusion.Pdf.Primitives.IPdfPrimitive obj, Syncfusion.Pdf.IO.PdfWriter writer) [0x001e0] in <96ea103c151d4af3b40ad4e62cdd8e90>:0
at Syncfusion.Pdf.IO.PdfCrossTable.SaveObjects (Syncfusion.Pdf.IO.PdfWriter writer) [0x0015f] in <96ea103c151d4af3b40ad4e62cdd8e90>:0
at Syncfusion.Pdf.IO.PdfCrossTable.Save (Syncfusion.Pdf.IO.PdfWriter writer) [0x0017d] in <96ea103c151d4af3b40ad4e62cdd8e90>:0
at Syncfusion.Pdf.Parsing.PdfLoadedDocument.AppendDocument (Syncfusion.Pdf.IO.PdfWriter writer) [0x0001b] in <96ea103c151d4af3b40ad4e62cdd8e90>:0
at Syncfusion.Pdf.Parsing.PdfLoadedDocument.Save (System.IO.Stream stream) [0x00114] in <96ea103c151d4af3b40ad4e62cdd8e90>:0
at Syncfusion.SfPdfViewer.XForms.Droid.ScrollViewEx.SaveDocument (System.Boolean flattenFormFields) [0x01847] in <f5d188b682d844b5a33023a93f840691>:0
at Syncfusion.SfPdfViewer.XForms.Droid.PdfDependencyServices.SaveDocument (System.Object nativeObject, System.Boolean flattenForm) [0x00015] in <f5d188b682d844b5a33023a93f840691>:0
at Syncfusion.SfPdfViewer.XForms.SfPdfViewer.SaveDocument () [0x0000c] in <284950a800324ed4875696ace3e0d1ee>:0
at ManualViewer.Views.PDFPhoneView.<Handle_BackButtonClicked>b__22_0 () [0x00000] in /Users/krikoz/Developer/ManualViewer/ManualViewer/Views/PDFPhoneView.xaml.cs:273
at System.Threading.Tasks.Task.InnerInvoke () [0x0000f] in <d4a23bbd2f544c30a48c44dd622ce09f>:0
at System.Threading.Tasks.Task.Execute () [0x00000] in <d4a23bbd2f544c30a48c44dd622ce09f>:0
Please let me know if you need any more information.