FastReport.NET v2021 打印预览报表出错NullReferenceException / RestoreEncodedText，踩坑！

FastReport.NET v2021 打印预览报表出错：

System.NullReferenceException:“未将对象引用设置到对象的实例。Void RestoreEncodedText()方法。

   at FastReport.RichTextParser.RTF_Parser.RestoreEncodedText()

   at FastReport.RichTextParser.RTF_Parser.ParseByte(Char ch)

   at FastReport.RichTextParser.RTF_DocumentParser.Load(Stream stream)

   at FastReport.RichObject.GenerateExpressionList()

   at FastReport.RichObject.CalculateExpressions()

   at FastReport.RichObject.GetData()

   at FastReport.BandBase.GetData()

   at FastReport.Engine.ReportEngine.PrepareBand(BandBase band, Boolean getData)

   at FastReport.Engine.ReportEngine.ShowBandToPreparedPages(BandBase band, Boolean getData)

   at FastReport.Engine.ReportEngine.ShowBand(BandBase band, Boolean getData)

   at FastReport.Engine.ReportEngine.ShowBand(BandBase band)

   at FastReport.Engine.ReportEngine.StartFirstPage()

   at FastReport.Engine.ReportEngine.RunReportPage(ReportPage page)

   at FastReport.Engine.ReportEngine.RunReportPages()

   at FastReport.Engine.ReportEngine.RunReportPages(ReportPage page)

   at FastReport.Engine.ReportEngine.Run(Boolean runDialogs, Boolean append, Boolean resetDataState, ReportPage page)

   at FastReport.Report.Prepare(Boolean append)

   at FastReport.Report.Show(Boolean modal, IWin32Window owner)

   at CSFrameworkV6.DemoReport.FastReportDemo.frmReportUser.DoPreview() in E:\Jonny's Project\CSFramework.V6.0 (旗舰版)\CSFrameworkV6.ClientFoundation\CSFrameworkV6.Report\FastReportDemo\frmReportUser.cs:line 41