Time for the slide continuing when movie is paused

• Create a T/F variable with the default value of False. 
• Add a trigger to change the state of the Next button to Disabled when the timeline starts with the condition that the variable = False. 
• Add a trigger to change the state of the Next button to Normal when the media (i.e., the video) completes. 
• Add a trigger to adjust the variable to True when the media completes. (This ensures the Next button won't be disabled if the user revisits the slide.) 

If you're not familiar with conditions and variables, here's more info: 

• https://community.articulate.com/series/articulate-storyline-360/articles/storyline-360-working-with-triggers#conditions 
• https://community.articulate.com/series/articulate-storyline-360/articles/articulate-storyline-360-user-guide-how-to-work-with-variables 

BTW, you can always override the built-in Restricted Navigation with triggers like that. Here's more info about ways to control the Next button:

• https://community.articulate.com/discussions/articulate-storyline/tip-controlling-the-next-button-101