Не могу создать сообщение в Оффлайн-клиенте. Вылетает эксепшен:

See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.ArgumentException: Font 'Arial' doesn't support style 'Regular'.
at System.Drawing.Font.Initialize(FontFamily family, Single emSize, FontStyle style, GraphicsUnit unit, Byte gdiCharSet, Boolean gdiVerticalFont)
at System.Drawing.Font.Initialize(String familyName, Single emSize, FontStyle style, GraphicsUnit unit)
at System.Drawing.Font..ctor(String familyName, Single emSize, FontStyle style, GraphicsUnit unit)
at System.Drawing.FontConverter.ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, Object value)
at System.ComponentModel.TypeConverter.ConvertFromString(String text)
at Rsdn.Scintilla.TextStyle..ctor(String name, Int32 number, Font font, Color foreColor, Color backColor, Boolean eolFilled, CaseMode caseMode, Boolean visible, Boolean hotSpot, PredefinedStyle predefinedStyle)
at RSDN.Janus.WriteMessageForm.InitializeComponent()
at RSDN.Janus.WriteMessageForm..ctor(Boolean edit, Int32 id)
at RSDN.Janus.WriteMessageForm..ctor(Int32 fid)
at RSDN.Janus.WriteMessageForm..ctor(Int32 fid, Int32 reply, String replynick, String subject, String body)
at RSDN.Janus.ForumDummyForm.ReplyMessage()
at RSDN.Janus.ForumDummyForm._tgMsgs_DoubleClick(Object sender, EventArgs e)
at System.Windows.Forms.Control.OnDoubleClick(EventArgs e)
at RSDN.TreeGrid.TreeGridBase.WmDblClk(Message& m, MouseButtons mbtn)
at RSDN.TreeGrid.TreeGridBase.WndProc(Message& m)
at System.Windows.Forms.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

В чем проблема? Как исправить?