How to fix the white screen of death error in WordPress?

Both PHP errors and database errors can manifest as a white screen, a blank screen with no information, commonly known in the WordPress community as the WordPress White Screen of Death (WSOD).

Before resorting to desperate measures, there are a number of reasons for the WordPress white screen of death:

• A Plugin is causing compatibility issues. If you can access the Administration Screens try deactivating all of your Plugins and then reactivating them one by one. If you are unable to access your Screens, log in to your website via FTP. Locate the folder wp-content/plugins and rename the Plugin folder plugins_old. This will deactivate all of your Plugins. You can read more about manually deactivating your plugins in the Troubleshooting FAQ.
• Your Theme may be causing the problem. This is especially likely if you are experiencing the white screen of death after you have just activated a new Theme, or created a New Site in a WordPress Network. Log in to the WordPress Administration Screens and activate the default WordPress Theme (e.g. Twenty Seventeen). If you can’t access your Administration Screens, access your website via FTP and navigate to the /wp-content/themes/ folder. Rename the folder for the active Theme.