Some of the free reseller themes comes with the problem that after theme activation, the option to add a featured image in a post does not show.
The solution is simple. Just follow these steps:
- Log in to your WordPress installation.
- Go to Appearance > Editor.
- Open the file functions.php
- Scroll to the end and add this code just before the end php tag ?>
add_theme_support( 'post-thumbnails' );