How to Fix a WordPress Site Stuck in Maintenance Mode
There are rare occassions when a website gets stuck in maintenance mode, this can be quite annoying at first; trying to find the solution and refreshing your website 100 times thinking it’s never going to work again.
You’ll be glad to know that there’s an easy fix available to work around this, however after following this tutorial you may need to contact the author of the theme or plugin if the issue persists after attempting the update for a second time.
If you’re stuck in WordPress maintenance mode, your WordPress Updater failed to delete the following file:
So you’ll need to delete it manually.
Log in to the file system of your website via FTP, or the Hosting Providers Control Panel and delete the file.
I hpe this helped you get your site working again, remember to always check your site after each update. If issues persist, consider replacing the plugin that caused the issue or disable the plugin using this tutorial.