Wordpress - Admin user can't update WP

I had this problem once.

You should check your wp-config.php file and if you find this line

define('DISALLOW_FILE_MODS',true);

change its value to false:

define('DISALLOW_FILE_MODS',false);

For anyone else with this problem, there is another line that you may have to find in your wp-config or functions file and change to false:

define('DISALLOW_FILE_EDIT', true);

WordPress was telling me I didn't have 'sufficient permissions' to update my own install even when logged in as the Administrator.
I had the following line in my wp-config.php file:
define('DISALLOW_FILE_MODS',true);
I was able to apply updates once again after I changed this line to:
define('DISALLOW_FILE_MODS',false);