When you analyze a button in the timeline of Adobe Captivate, you will notice it has 2 portions: an active and an inactive portion. Between these portions is a pause symbol.
The pause point stops the slide which allows the user to stay on the slide as long as he/she wants to without having to extend the slide duration. Keeping the slide duration length down helps minimize file size. Buttons cannot be clicked during the inactive part but they are still visible.
In order to get a slide to behave in the desired manner, many Captivate users will adjust the pause spot by dragging the bar on the Timeline to the right to give other objects enough time to appear before the slide action stops. But an easier approach can be done by removing the inactive part so that the play-head will continue without pausing. To do this, select the button and then go to the Timing portion of the Properties panel and deselect “Pause After”. This setting change will delete the pausing point and make the inactive part disappear.