Fatal Error when trying to load Permalinks page on WP admin [closed]

The error is related with the Hosting Server PHP Version. So if you are on PHP 7.3.XX try downgrading to 7.2.xx or 7.1.xx and see if that helps!

P.S. I was facing the same issue and had to downgrade to PHP 7.1 to fix it!

error code: 523