That property has effect only for Tabs which ContentPanes have child controls.
Warning: If error or exception happens on server or on client and that property is enabled, then full post backs can be triggered. In case of errors or other misbehavior,- that property should be disabled.
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