Posts not hidden

Not sure what has changed, however this plugin doesn’t seem to work anymore. I used it once sometime last year, and it worked like a charm. Hid my post that I didn’t want available in our resource section. A year later I’ve decided to use it again on a second post, but this time it won’t hide the post, and the first post I had hidden is now showing in our resource section. Is this plug-in no longer supported for latest version of WordPress?

The page I need help with: [log in to see the link]