SYMPTOMS
You ran an XAF WinForms application with FormStyle = Ribbon and UIType = TabbedMdi, typed a text to search into the menu box corresponding to the built-in FullTextSearchAction or a custom ParametrizedAction. After you press Enter or click the Search button an error occurs with one of the following call stacks:
Type: NullReferenceException
Message: Object reference not set to an instance of an object.
Data: 0 entries
Stack trace:
at DevExpress.XtraBars.Ribbon.ViewInfo.RibbonItemViewInfoCalculator.CalcEditItemViewInfo(Graphics graphics, RibbonItemViewInfo item)
at DevExpress.XtraBars.Ribbon.ViewInfo.RibbonItemViewInfo.CheckViewInfo(Graphics graphics)
at DevExpress.XtraBars.Ribbon.Drawing.RibbonItemPainter.DrawObject(ObjectInfoArgs e)
at DevExpress.Utils.Drawing.ObjectPainter.DrawObject(GraphicsCache cache, ObjectPainter painter, ObjectInfoArgs e)
…
Type: ArgumentException
Message: Parameter is not valid.
Data: 0 entries
Stack trace:
at System.Drawing.Graphics.get_PageUnit()
at DevExpress.Utils.AppearanceObject.CalcDefaultTextSize(Graphics g)
at DevExpress.XtraBars.Ribbon.ViewInfo.RibbonPageHeaderViewInfo.CalcBestHeight()
at DevExpress.XtraBars.Ribbon.ViewInfo.RibbonViewInfo.CalcTabHeaderHeight()
at DevExpress.XtraBars.Ribbon.ViewInfo.RibbonViewInfo.CalcConstants()
…
As a result, a big red cross (X) is also drawn instead of the ribbon surface:
SOLUTIONS
Go to your Download Manager (or try a free trial) to migrate to v16.2.4 or later directly, which is the most preferred option here. This issue has already been fixed by the XtraBars team: RibbonControl - NullReferenceException is thrown in the RibbonItemViewInfoCalculator.CalcEditItemViewInfo method
Please accept sincerely apologies from our XAF and XtraBars teams for all the inconvenience here.