The ‘Briefly Unavailable for Scheduled Maintenance’ error in WordPress happens when an update is underway and the .maintenance file wasn’t automatically removed by WordPress after the update.
The error is generated by WordPress and can happen after WordPress core, plugin or theme updates. You can use the steps below to fix the ‘Briefly Unavailable for Scheduled Maintenance’ error on your website.
1. Log in to your hosting control panel
2. Click on the File Manager
3. Double click on the domains folder
4. Locate your website domain name folder and double click it
5. Double click the public_html folder
6. Search for and locate a file called .maintenance
7. Right click on the .maintenance file
8. From the dropdown, select Remove
9. On the Remove File popup, toggle OFF To Trash to permanently delete the file
10. Click the Remove button
11. Return to your browser and reload your website