Reply To: "White Screen of Death"
V4.28 contains new support for child themes, which required some changes to how directories are referenced within the theme. This update may help. You’ll need to update theme and plugin files. Files have been removed from the theme folder, so you must overwrite the theme folder to ensure old templates are removed.
You could try installing the default WordPress themes too – twentysixteen, twentyfifteen etc. as it looks like the installation is trying to default to these – just so that you can get back to the admin screen.
I managed to bodge my installation when testing the child theme updates and got WSOD too. I had to edit the wp_options table in the database and reset entries where option_name is template, stylesheet and current_theme in order to get back to the admin screen.
Let me know how you get on with the latest version.