1- Installed Flarum 2.0 beta
2- prepared workbench folder for development
3- forked one of my extension to start the upgrade to 2.0
i've commented ALL the frontend and refactored the admin part following the docs
import Extend from 'flarum/common/extenders';
import app from 'flarum/admin/app';
return [
new Extend.Admin()
.setting(
() => ({
setting: 'acme-interstellar.coordinates', // This is the key the settings will be saved under in the settings table in the database.
label: app.translator.trans('acme-interstellar.admin.coordinates_label', {}, true), // The label to be shown letting the admin know what the setting does.
help: app.translator.trans('acme-interstellar.admin.coordinates_help', {}, true), // Optional help text where a longer explanation of the setting can go.
type: 'boolean', // What type of setting this is, valid options are: boolean, text (or any other <input> tag type), and select.
}),
30 // Optional: Priority
)
];
And i see this error

i also get this error if i try to edit an user from dashboard (with all extension disabled)
