Hi, several years ago we start to built a class library with Visual Studio 2012 for "Microsoft.NET Framework 2.0" and "SAP Crystal Reports runtime engine for .NET Framework (32-bit) version 13.0.5.891". The library with enabled "COM visibility" has functionality to print reports to a printer and the ability to open the CrystalDecisions.Windows.Forms.CrytsalReportsViewer on a report file. We could handle reports with included database connectivity and reports with ado net xml data. Now, I've migrated the library with Visual Studio 2015 to "Microsoft.NET Framework 4.0" and and "SAP Crystal Reports runtime engine for .NET Framework (32-bit) version 13.0.22.2668". For most of my tests, I have the following exception for both cases: opening the report viewer or printing to printer. Some tests are successful, and, additional, the earlier failed tests are successful. System.Runtime.InteropServices.SEHException (0x80004005): Eine externe Komponente hat eine Ausnahme ausgelöst. bei CrystalDecisions.Shared.PageRender.MeasureStringAccurate(String text, Font font, SizeF layoutArea, StringFormat format, Graphics g) bei CrystalDecisions.Shared.PageRender.draw_FieldObjectInstance(FieldObjectInstance fieldObject, Graphics g) bei CrystalDecisions.Shared.PageRender.draw_ReportObjectInstance(ReportObjectInstance instance, Graphics g, Rectangle clipRect) bei CrystalDecisions.Shared.PageRender.draw_SectionInstance(SectionInstance section, Graphics g, Rectangle clipRect) bei CrystalDecisions.Shared.PageRender.Render(PageObject page, Graphics g, Graphics device_g) bei CrystalDecisions.Windows.Forms.PageControl.OnPaint(PaintEventArgs e) bei System.Windows.Forms.Control.PaintWithErrorHandling(PaintEventArgs e, Int16 layer) bei System.Windows.Forms.Control.WmPaint(Message& m) bei System.Windows.Forms.Control.WndProc(Message& m) bei System.Windows.Forms.ScrollableControl.WndProc(Message& m) bei System.Windows.Forms.ContainerControl.WndProc(Message& m) bei System.Windows.Forms.UserControl.WndProc(Message& m) bei CrystalDecisions.Windows.Forms.PageControl.WndProc(Message& m) bei System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) bei System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) bei System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) I've rebuilded the functionality as an executable with an additional main view and I never got an error. A web search of the problem did not lead to fitting current results. Does somebody have an idea? Jörg