Services cannot communicate with each other.
Services show connection errors. Cannot access services via subdomains.
Services are not on the same Docker network or network does not exist.
Steps:
1. Verify all services are on `folkzone_net` network 2. Check network exists: `docker network ls` 3. Inspect network: `docker network inspect folkzone_net` 4. Ensure containers can resolve each other by name
Always define a shared network in docker-compose.yml and ensure all services use it.