Use of undefined constant NONCE_SALT

Cause

Salts are secret keys in WordPress, which provide a layer of security to your site. They are defined in the wp-config.php. If you see the error that the NONCE_SALT is undefined, that means your wp-config.php file does not define this salt.

The NONCE_SALT should have been automatically generated for you when you set up your site. If you check WordPress's sample wp-config.php file you can see all salts starting from line 51.

define( 'NONCE_KEY','put your unique phrase here' );

Solution

1

Generate a new NONCE_SALT at WordPress salt generator

2

Open your wp-config.php file (you can use FTP or your host's file manager) and paste the generated NONCE_SALT code.

If you find a commend that says /* That's all, stop editing! Happy blogging. */, you can paste the NONCE_SALT just after it.

If you don't see this comment, you can paste paste the NONCE_SALT from the second line.