may have problem when activate in Local WP has conflict

Hi @supakwong!

The linked documentation is correct about how this matter has to be resolved:

https://smartslider.helpscoutdocs.com/article/2014-use-of-undefined-constant-noncesalt

So the NONCE_SALT?constant is missing from your wp-config.php file, which should be there by default. You should follow our documentation to resolve the issue, and then everything will be fine!