Akka 1.4.3 fail repro

fallback1.hocon

  akka : {
    actor : {
      provider : cluster
    }
  }

fallback2.hocon

  akka : {
    stdout-loglevel : INFO
    loglevel : INFO
    log-config-on-start : on
    loggers : ["Akka.Logger.Serilog.SerilogLogger, Akka.Logger.Serilog"]
    actor : {
      debug : {
        receive : on
        autoreceive : on
        lifecycle : on
        event-stream : on
        unhandled : on
      }
    }
  }

fallback3.hocon

  akka : {
    remote : {
      dot-netty : {
        tcp : {
          log-transport : true
          transport-class : "Akka.Remote.Transport.DotNetty.TcpTransport, Akka.Remote"
          transport-protocol : tcp
          hostname : 0.0.0.0
          public-hostname : localhost
          port : 9000
        }
      }
    }
  }

fallback4.hocon

  akka : {
    cluster : {
      log-info : on
      seed-nodes : ["akka.tcp://System@localhost:9000"]
      roles : []
      role : {
      }
    }
  }

output.log

[INFO][3/23/2020 5:50:09 PM][Thread 0001][remoting (akka://System)] Starting remoting
[INFO][3/23/2020 5:50:10 PM][Thread 0001][remoting (akka://System)] Remoting started; listening on addresses : [akka.tcp://System@0.0.0.0:2552]
[INFO][3/23/2020 5:50:10 PM][Thread 0001][remoting (akka://System)] Remoting now listens on addresses: [akka.tcp://System@0.0.0.0:2552]
[INFO][3/23/2020 5:50:10 PM][Thread 0001][Cluster (akka://System)] Cluster Node [akka.tcp://System@0.0.0.0:2552] - Starting up...
[INFO][3/23/2020 5:50:10 PM][Thread 0001][Cluster (akka://System)] Cluster Node [akka.tcp://System@0.0.0.0:2552] - Started up successfully
[INFO][3/23/2020 5:54:48 PM][Thread 0023][Cluster (akka://System)] Cluster Node [akka.tcp://System@0.0.0.0:2552] - No seed-nodes configured, manual cluster join required
[info: Core.IMicroService[0]
      core-cluster-svc initialized successfully: Core.Hosting.MicroService`1[Core.Cluster.Service.Startup]
18:54:48 INF] ClusterService started
[18:54:48 INF]   akka : {
    actor : {
      provider : cluster
    }
  }

[18:54:49 INF] HTTP GET / responded with 404 in 4.6371 [ms]
[ERROR][3/23/2020 5:54:48 PM][Thread 0025][akka.tcp://System@0.0.0.0:2552/system/IO-TCP/$a] Bind failed for TCP channel on endpoint [0.0.0.0:9110]
Cause: System.Net.Sockets.SocketException (10048): Only one usage of each socket address (protocol/network address/port) is normally permitted.
   at System.Net.Sockets.Socket.UpdateStatusAfterSocketErrorAndThrowException(SocketError error, String callerName)
   at System.Net.Sockets.Socket.DoBind(EndPoint endPointSnapshot, SocketAddress socketAddress)
   at System.Net.Sockets.Socket.Bind(EndPoint localEP)
   at Akka.IO.TcpListener..ctor(TcpExt tcp, IActorRef bindCommander, Bind bind)
[ERROR][3/23/2020 5:54:48 PM][Thread 0022][akka.tcp://System@0.0.0.0:2552/user/petabridge.cmd] FATAL. petabridge.cmd host failed to bind to [0.0.0.0:9110]. Failure: [CommandFailed(Bind(addr: 0.0.0.0:9110, handler: [akka://System/user/petabridge.cmd#1830103343], backlog: 100, pullMode: False))]. Shutting down...
[INFO][3/23/2020 5:54:48 PM][Thread 0022][akka.tcp://System@0.0.0.0:2552/user/petabridge.cmd] Shutting down petabridge.cmd host...
[INFO][3/23/2020 5:54:48 PM][Thread 0004][akka://System/user/petabridge.cmd] Message [Bound] from akka://System/system/IO-TCP/$a to akka://System/user/petabridge.cmd was not delivered. [1] dead letters encountered .This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.

Pseudo.cs

// Pseudocode
var config = ConfigurationFactory.Empty;

foreach (var cfg in fallbacks)
{
  config = config.WithFallback(cfg);
}

return ActorSystem.Create("System", config);