Possible reason is a change in the WordPress Core, that a PHP function is not available any more and causes a “white page” when the website / WordPress is opened.
Even the WP-Admin Interface could not work anymore.
This function get_currentuserinfo() (https://codex.wordpress.org/Function_Reference/get_currentuserinfo) is used by some plugins & themes like
- ”Layerslider Plugin”
- “Cache-Enabler Plugin from Key-CDN”
- “W3 Total Cache“
- „WP Rocket“
As long there’s no update of the “problematic” plugins & themes, the only quick fix is to deactivate the plugin, switch the theme or downgrade WordPress to 4.4.2
Due the fact that in the most cases wp-admin is also broken the update of plugins is difficult we recommend the wp-cli tool, which is installed on all our Web-Hosting Servers by default.
Update or deactive plugins with the wp-cli
wp plugin update –all
If your wp-admin is still not reachable you may have to deactive some plugins. If you are still connected via ssh use this code snippet:
wp plugin deactivate <plugin-name>
To find out the right name of the plugin you can use the following command which returns you all installed plugins and marks the active ones:
wp plugin status