This exception reproduces only if the keytips are enabled and the ribbonview is set as a Content of RadPane (or RadTabItem) that is not selected, and also the MinimizeButtonVisibility property is set to Visible.

The error will occur also if the HelpButtonVisibility is set to Visible.

As a workaround you can set the MinimizeButtonVisibility to Collapsed. Then subscribe for the SelectionChanged event of the pane group and in its handler set the visibility to Visible only when the corresponding pane is selected.



Available in LIB version: 2016.2.725