Required: Set Frontpage to Latest Posts

To add widgets and display slider on your frontpage, Go to Settings > Reading from your WordPress Dashboard and make sure that your “Front Page Displays” option is set to “Your Latest Posts”. Even if you don’t have to display latest posts on your frontpage you will still have to make sure that the frontpage is set to that option. Don’t worry, you can easily replace the Posts with widgets by adding widgets from Customize > Frontpage > Frontpage Widgets. Once you add the widgets, the posts will be automatically replaced.