Error when connecting to the Gorgone server

I also face same issue. (Issue was I accidentally pasted poller configuration at central)
check you gorgone configuration 
cat /etc/centreon-gorgone/config.d/40-gorgoned.yaml it should be look like below

 

gorgone:
  gorgonecore:
    privkey: "/var/lib/centreon-gorgone/.keys/rsakey.priv.pem"
    pubkey: "/var/lib/centreon-gorgone/.keys/rsakey.pub.pem"
    id: 1

  modules:
    - name: httpserver
      package: "gorgone::modules::core::httpserver::hooks"
      enable: true
      address: "0.0.0.0"
      port: "8085"
      ssl: false
      auth:
        enabled: false
      allowed_hosts:
        enabled: true
        subnets:
          - 127.0.0.1/32

    - name: action
      package: "gorgone::modules::core::action::hooks"
      enable: true
      command_timeout: 30
      whitelist_cmds: true
      allowed_cmds:
        - ^sudo\s+(/bin/)?systemctl\s+(reload|restart)\s+(centengine|centreontrapd|cbd)\s*$
        - ^(sudo\s+)?(/usr/bin/)?service\s+(centengine|centreontrapd|cbd|cbd-sql)\s+(reload|restart)\s*$
        - ^/usr/sbin/centenginestats\s+-c\s+/etc/centreon-engine/centengine\.cfg\s*$
        - ^cat\s+/var/lib/centreon-engine/[a-zA-Z0-9\-]+-stats\.json\s*$
        - ^/usr/lib/centreon/plugins/.*$
        - ^/bin/perl /usr/share/centreon/bin/anomaly_detection --seasonality >> /var/log/centreon/anomaly_detection\.log 2>&1\s*$
        - ^/usr/bin/php -q /usr/share/centreon/cron/centreon-helios\.php >> /var/log/centreon-helios\.log 2>&1\s*$
        - ^centreon
        - ^mkdir
        - ^/usr/share/centreon/www/modules/centreon-autodiscovery-server/script/run_save_discovered_host
        - ^/usr/share/centreon/bin/centreon -u \"centreon-gorgone\" -p \S+ -w -o CentreonWorker -a processQueue$

    - name: cron
      package: "gorgone::modules::core::cron::hooks"
      enable: true
      cron: !include cron.d/*.yaml

    - name: nodes
      package: "gorgone::modules::centreon::nodes::hooks"
      enable: true

    - name: proxy
      package: "gorgone::modules::core::proxy::hooks"
      enable: true

    - name: legacycmd
      package: "gorgone::modules::centreon::legacycmd::hooks"
      enable: true
      cmd_dir: "/var/lib/centreon/centcore/"
      cmd_file: "/var/lib/centreon/centcore.cmd"
      cache_dir: "/var/cache/centreon/"
      cache_dir_trap: "/etc/snmp/centreon_traps"
      remote_dir: "/var/cache/centreon//config/remote-data/"

    - name: engine
      package: "gorgone::modules::centreon::engine::hooks"
      enable: true
      command_file: "/var/lib/centreon-engine/rw/centengine.cmd"

    - name: statistics
      package: "gorgone::modules::centreon::statistics::hooks"
      enable: true
      broker_cache_dir: "/var/cache/centreon//broker-stats/"
      cron:
        - id: broker_stats
          timespec: "*/5 * * * *"
          action: BROKERSTATS
          parameters:
            timeout: 10
        - id: engine_stats
          timespec: "*/5 * * * *"
          action: ENGINESTATS
          parameters:
            timeout: 10

and after this restart gorgone service
systemctl restart gorgoned