how to change a "book component" to a "topic" in a book document?

Explorer ,

Hi!

I am publishing a .book to html5 and as I view the output, my browser cannot find one page eventhough the path and the location seems is correct. Now, in Framemaker sturcture view the said file shows as "book component" not as "topic" as all the other files. Is this the problem and how do I fix it?

TOPICS

Responsive HTML5 , Structured