Line Suppression State Error CS1056 Unexpected character '​'

I'm doing this code to save files from syntaxEditor

but I'm getting the error Unexpected character '​' when compiling

       public void saveascommand()
        {
            Microsoft.Win32.SaveFileDialog dlgs = new Microsoft.Win32.SaveFileDialog();
            dlgs.FileName = "Document"; // Default file name
            dlgs.DefaultExt = ".text"; // Default file extension
            dlgs.Filter = "C# (.cs)|*.cs|VB.NET (.vb)|*.vb|HTML (.html)|*.html|JavaScript (.js)|*.js|XML (.xml)|*.xml|XAML (.xaml)|*.xaml|SQL (.sql)|*.sql"; // Filter files by extension
            Nullable<bool> result = dlgs.ShowDialog();
            if (result == true)
            {
                File.WriteAllText(dlgs.FileName, string.Empty);
                using (StreamWriter sw = File.AppendText(dlgs.FileName))
                {
                    ​syntaxEditor.Document.SaveFile(dlgs.FileName, LineTerminator.CarriageReturnNewline);
                    filename = System.IO.Path.GetFileName(dlgs.FileName);
                    filepath = dlgs.FileName;
                    savedfirsttime = true;
                    Title = "ProCode | " + filename;
                }
            }


        }