Why do plugins/themes fail to update?
The most common cause of this problem is that your website requires FTP information.
You can correct upgrade issues by adding FTP information in your site’s wp-config.php file.
Note: Do not add this to the end of the file, but just below the database information on the top of the file.
define('FTP_USER', 'username'); define('FTP_PASS', 'password'); define('FTP_HOST', 'ftp.example.org');
More complex update methods like FTPS or SSH are also supported if you enter the appropriate details in the wp-config.php file. For more information on FTP/SSH upgrades, click here.