He verificado /var/discourse/app/views y parece que no existe esa carpeta.
Ejecuté el comando: ls -d /var/discourse/*
Y solo mostró algunos directorios:
/var/discourse# ls -d /var/discourse/*
/var/discourse/bin /var/discourse/discourse-doctor /var/discourse/launcher /var/discourse/samples /var/discourse/templates
/var/discourse/cids /var/discourse/discourse-setup /var/discourse/LICENSE /var/discourse/scripts /var/discourse/Vagrantfile
/var/discourse/containers /var/discourse/image /var/discourse/README.md /var/discourse/shared
¿Cómo puedo solucionarlo?