[Resolved] 404 error on all single record displays

Hi, I can see how this is a serious problem. I'll try to help as best I can. Please try these troubleshooting steps first:
- Temporarily deactivate all plugins except Types and Views, then activate a default theme like Twenty Seventeen. If you want to use a plugin like Maintenance Mode to disable the site from users while you're testing that will be fine. Resave your permalinks and test again in this minimum setup.
- If the problem is resolved, that indicates a conflict somewhere. Please activate your theme and plugins one-by-one until the problem is revealed. You may have to resave permalinks each time you activate another plugin.
- If the problem was not resolved, continue.
- Access your server logs to see if any errors are being thrown that could be causing your server to display a 404 message instead of the actual post. If you do not have access to your logs or know where to get them, go in your wp-config.php file and look for define(‘WP_DEBUG’, false);. Change it to:

define('WP_DEBUG', true);

Then add these lines, just before it says 'stop editing here':

ini_set('log_errors',TRUE);
ini_set('error_reporting', E_ALL);
ini_set('error_log', dirname(__FILE__) . '/error_log.txt');

Now try to load a student page again. If any errors are thrown, this will create an error_log.txt file in your site's root directory. Please send me its contents. Once that is done, you can revert the updates you made to wp-config.php.

I'll review your logs and determine how best to proceed.