Fix BackgroundJobError

✅ Solution

BackgroundJobError in Devise often arises from `deliver_later` calls within Devise mailers failing due to transaction issues during testing or inconsistent configurations. To fix this, configure your test environment to use `deliver_now` for Devise emails by setting `config.action_mailer.delivery_method = :test` and `config.action_mailer.perform_deliveries = true` in `config/environments/test.rb`, or ensure asynchronous delivery mechanisms are properly set up and reliable in all environments. Examine Devise initializers for potentially incorrect configurations.