Hi @techskaps,

The WordPress.org software displays a critical error message when something on the site, usually a plugin or theme, is causing an error that is preventing the site from working.

WordPress sends an email to the site administrator with more details about the error. If you’re not able to find that email, I’d recommend checking the PHP error logs in your web hosting account. If you’re not sure how to access those logs, your web host can help you.

The full error message should include the name of the plugin or theme causing the error. You can remove that plugin or theme to remove the error and get the site working again.

—

Generally speaking, other plugins you have installed on your site can cause issues like this.
 
Have you done any initial troubleshooting yet? If not, please rule out a theme issue or a plugin conflict. I recommend testing things on a staging site rather than on your production (live) site. Many hosts provide a staging service, where you can do testing without affecting the live site. You can ask your host about this. If they don’t give you a staging site, you could try WP Staging or Duplicator:
 
https://wordpress.org/plugins/wp-staging/
https://wordpress.org/plugins/duplicator/
 
First, temporarily switch to Twenty Seventeen, which is one of the default WordPress themes. You can do this by installing a plugin that only switches the theme for the current user, linked below:
 
https://wordpress.org/plugins/theme-switcha/
 
If the critical notice disappears, it means the theme is causing the issue and you’ll need to contact your theme’s developer to see if they can help you troubleshoot.
 
If things still don’t work properly with Twenty Seventeen, please try checking for conflicting plugins.
 
To do so, temporarily disable all plugins but WP Job Manager (and related addons), and see if the issue resolves. If it does, try activating your plugins one-by-one and try to reproduce the problem. If it comes back when you activate a particular plugin, you’ve found the culprit.
 
A side-note; before you deactivate your plugins, we recommend that you make a full backup of your site.
 
If you’d rather not create a staging site, Health Check is a tool that can be useful for debugging, though it requires an official default theme like Twenty Seventeen. On the troubleshooting tab, you can click the button to disable all plugins and change the theme for you while you’re logged in to that session without affecting normal visitors to your site.