Q:

Docker Error When Starting Docker-Compose Project

When running docker-compose up -d on a project that previously was running (for weeks), I get the following error when building a web container:
» |root|  ‡ master * docker-compose up -d
Starting gateway_web_1

ERROR: for web  Cannot start service web: updating the store state of sandbox failed: failed to update store for object type *libnetwork.sbState: json: cannot unmarshal string into Go struct field sbState.ExtDNS of type libnetwork.extDNSEntry
ERROR: Encountered errors while bringing up the project.

I have restarted the Docker service, I have reinstalled Docker, but I cannot get past that error, and I have run out of places to look. 
Here is my docker-compose.yml
version: '2'
services:
  web:
    build: ./docker-lemp
    ports:
      - 8080
    networks:
      - front-tier
      - back-tier
    volumes:
      - ./public:/var/www
      - ./default:/etc/nginx/sites-enabled/default

  redis:
    image: redis
    ports:
      - <public IP>:6379:6379
    links:
      - web
    networks:
      - back-tier
      - front-tier

  lb:
    image: dockercloud/haproxy
    ports:
      - <public IP>:443:443
      - <public IP>:80:80
    links:
      - web
    networks:
      - front-tier
      - back-tier
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - ./haproxy/haproxy.cfg:/etc/haproxy/haproxy.cfg
    environment:
    <SSL stuff>
networks:
  front-tier:
    driver: bridge
  back-tier:
    driver: bridge

Thanks!

A:

This was resolved by deleting the Docker datastore, using rm -rf /var/lib/docker. After then restarting Docker (which recreated the datastore), the issue was resolved and Docker was once again able to create and start containers.

