Some Wordpress users have reported a bug, unofficially known as the 'Wordpress white page of death'. This may occur when Wordpress is unable to display the content on an administration page. Here are some possible reasons and potential fixes:
Cause: Plugins may be incompatible or improperly installed
Fix: Disable all plugins
Cause: The theme is not displaying
Fix: Log into ssh or ftp and go to wp-content, theme. From there you should see multiple themes. Search for one that has a custom name or go to phpmyadmin and load the wp_options table and find the variable current_theme. Rename the theme as nameofthetheme.backup and rename twentyeleven (theme by default) to nameofthetheme.
Cause: PHP 5.4 incompatible
Fix: Manually update Wordpress or downgrade to 5.3 and re-upgrade again to 5.4.