The second admin with full permissions can't access to update.php

User with "admin role" assigned with module Admin Role can't access to update.php. So the second admin (user which role is an "administrator" role with full permissions) can't get access to update.php process. The first admin (user uid = 1) can.

It tells:

Access denied

Access denied. You are not authorized to access this page. Please log in as the admin user (the first user you created). If you cannot log in, you will have to edit settings.php to bypass this access check. To do this:

1. With a text editor find the settings.php file on your system. From the main Drupal directory that you installed all the files into, go to sites/your_site_name if such directory exists, or else to sites/default which applies otherwise.
2. There is a line inside your settings.php file that says $update_free_access = FALSE;. Change it to $update_free_access = TRUE;.
3. As soon as the update.php script is done, you must change the settings.php file back to its original form with $update_free_access = FALSE;.
4. To avoid having this problem in future, remember to log in to your website as the admin user (the user you first created) before you backup your database at the beginning of the update process.

But it's set as TRUE all time.