You should not need a Next button on the default quiz slides at all. This is the default design of a quiz slide (functionality is built in the embedded objects, where Submit button is the main player):
- User clicks on Submit button and the first step happens, while the quiz slide remains paused: the feedback messages appear (all can be customized per slide). The message is to click on the slide or press Y to continue.
- When the user does click on the slide or presses Y the playhead is released, the actions specified under Succes or Last Attempt are executed, unless the user has still an attempt left on the slide. You can set both actions to 'Go to Next Slide', no need for a Next button.
What do you want to change, maybe I could offer some ideas for tweaking that normal design. In this article you'll see some of them, but have to upgrade. I am very happy that the former 'Next' button which doubled as Skip button is gone, because it caused a lot of confusion for the learners. You seem to want it back?
Question Question Slides in Captivate - Captivate blog