How to recover wordpress from "Briefly Unavailable for Scheduled Maintenance Error in WordPress"

A common problem when updating WordPress on a shared hosting is that the update process may be timeout due to server load or memory exhausted (Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 13897 bytes) in /home/xxxxx/public_html/wordpress/wp-includes/update.php on line 201) when site or plugin update interrupts this will leaving your site in maintenance mode just show this msg "Briefly Unavailable for Scheduled Maintenance Error in WordPress"

 Here i can explain how to recover wordpress from "Briefly Unavailable for Scheduled Maintenance Error in WordPress".

Normally when updating wordpress core or plugin a .maintenance file will be created on your wordpress installtion root. During the update process, WordPress downloads necessary update files to your server, extracts them, and installs new files. WordPress also puts your site on maintenance mode and displays the “Briefly unavailable for scheduled maintenance” notice during this process.

 To fix this issue simple delete the .maintenance file and make sure the wordpress successfully updated if not please update manually. Once you have deleted this file your site back to normal.