Board unaccessible after upgrade

[Hifihedgehog]

Great! Alternatively, Ember 3 can still be manually enabled via a flag in your app.yml file if you have a need in your user base to preserve Retort functionality. Per Discourse, however, that flag will eventually not work as the Ember 3 compatibility mode will be gutted entirely. The ETA of that I last read was Q1 so in the next couple months or sooner, that fallback compatibility mode will be deprecated.