I got the WSOD in admin only during a plugin update, and it turned out to be Custom Sidebars Pro.
I got this from debug:
Fatal error: Call to undefined method TheLib3_Wrap::get_version() in /var/www/html/wp-content/plugins/custom-sidebars/inc/external/wpmu-lib/inc/class-thelib-ui.php on line 342
Then I tried to disable the plugin via the Hub (since it broke my access to the plugin page) and got a message that "Deactivation failed". So I renamed the plugin folder, and boom, I've got my admin back.
Anyway, I'm ok for now but want to be able to run this plugin on my site, so if it can be fixed or we can sort out the conflict, that would be great :slight_smile: