Next Button State is Normal at Beginning of Timeline

A duplicate of this question has already been answered/solved here: Storyline 360: Next Button State is Normal at Beginning of Timeline | Articulate - Community 

SChen-65​: I don't know how/why this question was duplicated.

Posting copies of the same question can lead to wasted effort for the volunteers who answer questions here in the community. It also makes it harder for others to find the solution when they're searching to see if a question they have has already been answered. Please be more careful to ensure you only post a given question once.

By the way, if you're tempted to repost a question because the original has a mistake, or you forgot to attach a file, or something like that, instead you can edit the original post. The Edit option is available if you click the gear icon near the upper right corner of the page.