Shinyproxy error 500 :Failed to start container

Question

I encountered Error 500 when I try to run shinyproxy. these are the errors I got.

Caused by: com.spotify.docker.client.exceptions.DockerException: java.util.concurrent.ExecutionException: javax.ws.rs.ProcessingException: org.apache.http.conn.HttpHostConnectException: Connect to localhost:2375 [localhost/127.0.0.1] failed: Connection refused (Connection refused)

Caused by: java.util.concurrent.ExecutionException: javax.ws.rs.ProcessingException: org.apache.http.conn.HttpHostConnectException: Connect to localhost:2375 [localhost/127.0.0.1] failed: Connection refused (Connection refused)

And application.yml

proxy:
  title: Open Analytics Shiny Proxy
  logo-url: http://www.openanalytics.eu/sites/www.openanalytics.eu/themes/oa/logo.png
  landing-page: /
  heartbeat-rate: 10000
  heartbeat-timeout: 60000
  port: 3838
  authentication: simple
  admin-groups: scientists
  hide-navbar: true
  # Example: 'simple' authentication configuration
  users:
  - name: jack
    password: password
    groups: scientists
  - name: jeff
    password: password
    groups: mathematicians
  # Example: 'ldap' authentication configuration
  ldap:
    url: ldap://ldap.forumsys.com:389/dc=example,dc=com
    user-dn-pattern: uid={0}
    group-search-base:
    group-search-filter: (uniqueMember={0})
    manager-dn: cn=read-only-admin,dc=example,dc=com
    manager-password: password
    # Docker configuration
  docker:
    cert-path: /home/none
    url: http://localhost:2375
    port-range-start: 20000
  specs:
  - id: Try2
    display-name: Try2
    description: Application which demonstrates the basics of a Shiny app
    port: 3838
    container-cmd: ["R", "-e", "shiny::runApp('/root/euler')"]
    container-image: gokce/euler
    access-groups: [scientists, mathematicians]


logging:
  file:
    shinyproxy.log

I read some comments on windows firewall may cause the problem so I allowed port:3838 in windows firewall. But didnt help