Error on module admin configuration page
This is because the page rendering stopped when an error occurred. By default, Drupal does not display such kind of errors.

Enable your error reporting by temporarily editing your index.php file (normally located in your root directory) directly after the first opening PHP tag to add the following:

&lt;?php
error_reporting(E_ALL);
ini_set('display_errors', TRUE);
ini_set('display_startup_errors', TRUE);


After you edited the file, run your site and see what error came out.

WSOD is not directly related to this question, but it may be useful for you to tackle down your problem. It will help you to find out invisible errors.