Reason for app rejection: Guideline 1.3 - Safety > Kids Category

You have selected the Kids category for your app, but your app does not appear to be designed specifically for kids aged 11 and under. 

Please resubmit your app without the Kids category designation.

What does it mean?

How to resolve it? 

Uncheck the "Made for Kids" selection under Age Rating - Advanced setting, and resubmit the app.

Do I need to generate a new build?

No.