A disabled UltraWebToolbar attempts to ignore client-side interactivity. Making the buttons of an UltraWebToolbar that has been disabled appear grayed out is done by developers specifying the DisabledImage on any TBarButton instances, and changing the items' DefaultStyle to one more representative of a "disabled" appearance. Other toolbar items will have their text grayed-out, if supported by the end user's browser. Some browsers may not support graying-out of text, which is done through modern HTML Recommendation attributes.
While the UltraWebToolbar is disabled, developers should not change the Enabled state of any contained controls or toolbar items or add/remove items. Disabling the UltraWebToolbar will preserve a snapshot of the enabled state of existing items, that will be restored when the UltraWebToolbar is re-enabled. The behavior of manipulating the Items collection, or enabling items while UltraWebToolbar is disabled, is undefined.
Observe that when the control is operating with EnableViewState turned off, it becomes the responsibility of the developer to preserve and restore a snapshot of items' enabled states in whatsoever means best suits their web application.
Why enabling TBarButton while UltraWebToolbar is disabled fails?Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2