Window is Getting shrink while using RadFlowDocument Control

Hi,

I have written the below code on VS 2017 form button click suddenly the form is getting shrink. Please help me to solve this issue

using Telerik.Windows.Documents.Flow.Model;

Telerik.Windows.Documents.Flow.Model.RadFlowDocument document = new Telerik.Windows.Documents.Flow.Model.RadFlowDocument();
            Telerik.Windows.Documents.Flow.Model.Editing.RadFlowDocumentEditor editor = new Telerik.Windows.Documents.Flow.Model.Editing.RadFlowDocumentEditor(document);
            editor.InsertText("Hello world!");


            using (Stream output = new FileStream(@"c:\logs\output.docx", FileMode.OpenOrCreate))
            {
                Telerik.Windows.Documents.Flow.FormatProviders.Docx.DocxFormatProvider provider = new Telerik.Windows.Documents.Flow.FormatProviders.Docx.DocxFormatProvider();
                provider.Export(document, output);
            }