Hi 
It looks like a very recent update to Discourse Core (over the June 6–7 weekend) has introduced a breaking architectural change that causes the discourse-custom-wizard plugin to crash the entire application boot cycle.
Even attempting to visit /safe-mode fails with a global 500 error because the crash occurs during initialization middleware registration.
Here is the exact fatal error trace pulled from Logster:
ActionView::Template::Error (undefined method 'admin_stylesheets' for class DiscoursePluginRegistry)
lib/stylesheet/manager/builder.rb:199:in `Stylesheets::Manager::Builder#plugins_digest'
It appears that during the asset/stylesheet compilation phase (plugins_digest), core Discourse is invoking an admin_stylesheets method on the DiscoursePluginRegistry which is throwing an undefined method exception, likely due to a mismatch with how the custom wizard registers or extends administrative styles.
Disabling the plugin in app.yml and running a complete container rebuild allows the forum to boot normally, confirming the crash is isolated to the wizard’s integration hooks.
Could you please look into updating the registry/stylesheet hooks for compatibility with current core changes?
Thanks!