1) Category should be assigned to a store.

http://support.themeburn.com/wp-content/uploads/2016/11/categories_step_5.png

Menu block

2) Make sure your categories have the option “Top” selected.

http://support.themeburn.com/wp-content/uploads/2016/11/categories_step_1.png

3) If theme cache is enabled, you need to clear it every time a new category is added. The other option is to disable cache until all categories are entered.

http://support.themeburn.com/wp-content/uploads/2016/11/categories_step_2.png

Categories block

4) You should either have the option “Top” selected or disable the option that checks if the field is selected.

http://support.themeburn.com/wp-content/uploads/2016/11/categories_step_3.png

5) If theme cache is enabled, you need to clear it every time a new category is added. The other option is to disable cache until all categories are entered.

http://support.themeburn.com/wp-content/uploads/2016/11/categories_step_2.png

6) If theme content cache and categories block cache is enabled, you need to clear theme cache to rebuild block markup.

http://support.themeburn.com/wp-content/uploads/2016/11/categories_step_4.png