MySQL Host Address Not Working

If you’re seeing a blank page, it’s possible your website has crashed with an HTTP Error 500. To see the actual issue, you can set Display Errors to on in your control panel, and if that does not work, temporarily rename your .htaccess file to see if any rule in it is causing this. For more information, you can check this article:

As @Frank419 mentioned above, however, without more information (for example, the URL of your page, and your code if you want us to help you troubleshoot) we cannot be of much help.