Question

After the upgrade to WordPress 3.5 i have this Fatal error:

Cannot redeclare wp_explain_nonce() (previously declared in wp-includes/functions.php:1858) in /wp-includes/deprecated.php on line 3176

This is the function wp_explain_nonce() deprecated by this version.

What can i do to fix?

Answer 1

This usually happens when an update was interrupted or corrupted in some way. Here’s how to fix it(usually):

Use FTP client to get to your server and delete the /wp-admin, /wp-includes directories and all files in the directory where wp-admin and wp-includes were, except for wp-config.php and any other custom files that you might have had in there.

Then upload all files manually – download the latest WP version from here, extract it to your computer and upload all files to your server.

If you don’t want to delete your old files(which is always a good idea), just create a dummy directory, for instance /~backup and move all of the files and directories there(except /wp-content/ directory and /wp-config.php file).