White or Blank Page After Pushing | Fix Fatal Error 500

In very rare cases it’s possible that due to a plugin conflict on the staging and live site you get a blank page after running the pushing process.
In that case one of the plugins on the live site is causing a fatal error. You can fix that quickly in a minute by following the steps below:

Step 1 Find the Error Making plugin

You can find out what plugin is causing the error by enabling the wordpress debug.log.  After enabling the WordPress debug log reload the website and open the debug.log to check the recent errors in it.

Look for any recent line that mentions PHP Fatal Error

A complete error line could be looking like that

[13-Jun-2018 11:14:46 UTC] PHP Fatal error: Class 'ComposerAutoloaderInite9c6e5ee7d69a67b5104383b338dc6e0' not found in /home/content/a2pewpnas01_data02/63/4088363/html/wp-content/plugins/wordpress-seo/vendor/autoload_52.php on line 7

You can see here that the plugin wordpress-seo (Yoast) is throwing a fatal error.

Step 2 Delete the Error Making Plugin

When you’ve found out what plugin is causing the error on your website use any  FTP program and delete the corresponding plugin folder or just rename it. Both actions have the same effect and will deactivate the plugin on your website.

You find all WordPress plugins in the folder wp-content/plugins.

That’s it.
Your website is reachable again. Now you can move on and either push the plugin again from the staging site with WP Staging Pro or install it again from its original source like the wordpress plugin repository by installing it from wordpress > wp-admin > plugins.