Message : Briefly unavailable for Scheduled maintenance. Check back in a minute
I have issues with upgrading my WordPress version and upgrade version of my WordPress plugin. It happens when I upgrade the version of WordPress and plugin, the upgrade process was failed and got stuck in maintenance mode and returns this error message on my WordPress site. It was discussed on WordPress forum.
What Causes the Problem
The error message is to prevent the visitors of websites dealing with the broken pages and preventing the world or yourself from accessing your WordPress site during the upgrade process. When WordPress automatically update WordPress core files or it’s plugin, WordPress site will be in maintenance mode. This problem occurs when the maintenance process failed half way and was not complete at the end of the process. Sometimes the problem is caused by the web server response is too slow or the server memory resources shortage and update script will probably gets interrupted and time out.
“Briefly unavailable for Scheduled maintenance. Check back in a minute”
Fortunately, the solution is very easy to implement. You can simply delete the .maintenance file from the WordPress root directory or just rename it to other file name. After you have deleted a file or renamed files, you will be able to access the site as usual, but you may need to execute the automatic upgrade process again.
If you are using a web interface such as CPanel File Manager, you may need to specify that you want to see hidden files (dotfiles).
If the problem occurs while upgrading the plugin, rename your plugin folder to something else and other then ‘plugins’ that will automatically deactivate your plugins and allows you to gain access to your WordPress site again.
After you successfully remove the warning message, please be sure to check the category and tag the links in your WordPress site works without any internal server error.