RapidFire, as an engine, has it's own root
which is mounted under the /surveys
path that you specified. Calling root_path
from within a RapidFire namespaced controller/view will refer to the that root - not the sitewide root.
To fix this, you can pass the sitewide root path to the engine, and call that from the header instead - see Rails.root from engine for a way to do this.