How to fix briefly unavailable for scheduled maintenance in Wordpress

If during a theme or plugin update your screen got stuck and after you refreshed the page you get:

Briefly unavailable for scheduled maintenance. Check back in a minute.

Here is how to fix it.

When Wordpress is doing any updates creates a .maintenance file in the root directory of the installation. The file is auto-removed after the updates are done.

In the case of an interruption of some sort, this file doesn't get deleted and the message won't go away. The causes can vary from one installation to other, it can be a plugin issue or if your server is not powerful enough you might run out of memory during the update. If it happens really often the chance of running out of memory is really high. You can check the server logs for details.

Steps

• Log into your web server via FTP or your web host's control panel.
• Locate the root of your WordPress install (first place to look /var/www/html/)
• Look for a file called .maintenance
• Delete it
• Refresh your WordPress site

The site should back now. If still doesn't work try the following:

• Find the file called wp-activate.php in the root directory,
• Edit and search for WP_INSTALLING parameter (should be at the beginning of the file).

• change it from true to false.

  define(<<WP_INSTALLING>>, true);

  to

  define(<<WP_INSTALLING>>, false);