Having a theme with an older version of Sp Page Builder Pro may give you an error resulting in a blank administrator page when you update Joomla to the latest version.
If you are in this situation, you can reinstall our quickstart pack and update Sp Page Builder Pro before you update Joomla. If you do not want to reinstall, please check the solution available here: http://blog.payo-themes.com/joomla-3-8-white-blank-backend-after-update-fix/