Wordpress Upgrade failed. Admin panel not working

Question

I wanted to Upgrade the Wordpress installation, I clicked on the Upgrade to latest version link from my WP ADMIN panel and post that it has asked me to give FTP details for the Update for which FTP details were entered and Upgrade started. After few minutes I got Below ERROR and Now WP ADMIN is not loading. I tried to clear browser cache and cookies but still not working. Please Help in resolving the issue.

There has been a critical error on your website. Please check your site admin email inbox for instructions.

Learn more about debugging in WordPress.

I have further tried to debug and added below code in wp-config but i am not getting any errors on the page neither in the path /wp-content/debug.log file is there.

// Enable WP_DEBUG mode
define( 'WP_DEBUG', true );
// Enable Debug logging to the /wp-content/debug.log file
define( 'WP_DEBUG_LOG', true );
// Disable display of errors and warnings
define( 'WP_DEBUG_DISPLAY', false );
@ini_set( 'display_errors', 0 );
// Use dev versions of core JS and CSS files (only needed if you are modifying these core files)
define( 'SCRIPT_DEBUG', true );

Answer 1

Reference: https://wordpress.org/support/topic/wordpress-upgrade-failed-wp-admin-panel-not-working/

Dear users, please use manual update if you can't update automatically.

See here:

Updating WordPress

You can do it with cpanel:

1. Simple copy wp-content & wp-config.php to a directory out of public_html (for example, create a folder by name “backupold” and put files in it)
2. Download latest version https://wordpress.org/latest.tar.gz
3. Upload it in your wordpress directory (output file will be in public_html/wordpress for example)
4. Copy (backuped contents) “wp-content” folder & “wp-config.php” file to “wordpress” folder & replace
5. Move all files and folders from “wordpress” folder to your site directory (by default, public_html) & replace.

Now enjoy!

Warning: do a backup before, and do as i say enter code here