A quick fix for “Briefly unavailable for scheduled maintenance. Check back in a minute.” error.
Why do we get this?
This notice shows up when the WordPress core, plugins and themes are being updated. WordPress creates a temporary .maintenance file in your installation folder and puts your site in maintenance mode while it’s updating.
Normally, this “Briefly unavailable for scheduled maintenance.” notice automatically gets deleted once everything has been done updated, however, sometimes due to slow hosting, theme or plugin compatibility issues, low memory or disk usage issue, the update script times out and that temporary file doesn’t get deleted.
To quickly fix this, login to your control panel, file manager or ftp, look for the .maintenance file in your installation folder and delete it. Make sure that you enabled to view hidden files to see the file.