Not sure if this is a server setup thing or happens to all installs, but my upload image button was producing an error about not being able to create a directory.
In case you are having the same problem, here is what I did to fix it:
- Go into wp-content/plugins/rich-widget/config.php on line 8
- Change the path to your own images folder and remove the last slash in the second parameter - it will probably look like this:
define('RB_RICHWIDGET_FILEPATH', realpath(dirname(__FILE__) . '/../../uploads/rich-widget') . '/');
define('RB_RICHWIDGET_FILEPATH', realpath(dirname(__FILE__) . '/../../images') . '');