Unable to start elasticsearch 7.4.2 - error during startup - elasticsearch

Question

I get the following error when starting up elasticsearch 7.4.2 on Windows 10 platform. I download the zip file, unzipped it and tried started it using elasticsearch.bat. I also tried updating the elasticsearch.yml to change the port and host name, but nothing works. Could anyone help with this one? Thanks.
[2019-11-30T00:26:06,319][WARN ][o.e.b.ElasticsearchUncaughtExceptionHandler] [ABHATIA-P51] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.IllegalStateException: failed to create a child event loop
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:163) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:150) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:125) ~[elasticsearch-cli-7.4.2.jar:7.4.2]
at org.elasticsearch.cli.Command.main(Command.java:90) ~[elasticsearch-cli-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:115) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:92) ~[elasticsearch-7.4.2.jar:7.4.2]
Caused by: java.lang.IllegalStateException: failed to create a child event loop
at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:88) ~[?:?]
at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:58) ~[?:?]
at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:47) ~[?:?]
at io.netty.channel.MultithreadEventLoopGroup.<init>(MultithreadEventLoopGroup.java:59) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:78) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:73) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:60) ~[?:?]
at org.elasticsearch.transport.netty4.Netty4Transport.doStart(Netty4Transport.java:134) ~[?:?]
at org.elasticsearch.xpack.core.security.transport.netty4.SecurityNetty4Transport.doStart(SecurityNetty4Transport.java:81) ~[?:?]
at org.elasticsearch.xpack.security.transport.netty4.SecurityNetty4ServerTransport.doStart(SecurityNetty4ServerTransport.java:43) ~[?:?]
at org.elasticsearch.common.component.AbstractLifecycleComponent.start(AbstractLifecycleComponent.java:59) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.transport.TransportService.doStart(TransportService.java:230) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.common.component.AbstractLifecycleComponent.start(AbstractLifecycleComponent.java:59) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.node.Node.start(Node.java:695) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Bootstrap.start(Bootstrap.java:273) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:358) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:159) ~[elasticsearch-7.4.2.jar:7.4.2]
... 6 more
Caused by: io.netty.channel.ChannelException: failed to open a new selector
at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:180) ~[?:?]
at io.netty.channel.nio.NioEventLoop.<init>(NioEventLoop.java:146) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:138) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:37) ~[?:?]
at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:84) ~[?:?]
at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:58) ~[?:?]
at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:47) ~[?:?]
at io.netty.channel.MultithreadEventLoopGroup.<init>(MultithreadEventLoopGroup.java:59) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:78) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:73) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:60) ~[?:?]
at org.elasticsearch.transport.netty4.Netty4Transport.doStart(Netty4Transport.java:134) ~[?:?]
at org.elasticsearch.xpack.core.security.transport.netty4.SecurityNetty4Transport.doStart(SecurityNetty4Transport.java:81) ~[?:?]
at org.elasticsearch.xpack.security.transport.netty4.SecurityNetty4ServerTransport.doStart(SecurityNetty4ServerTransport.java:43) ~[?:?]
at org.elasticsearch.common.component.AbstractLifecycleComponent.start(AbstractLifecycleComponent.java:59) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.transport.TransportService.doStart(TransportService.java:230) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.common.component.AbstractLifecycleComponent.start(AbstractLifecycleComponent.java:59) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.node.Node.start(Node.java:695) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Bootstrap.start(Bootstrap.java:273) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:358) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:159) ~[elasticsearch-7.4.2.jar:7.4.2]
... 6 more
Caused by: java.io.IOException: Unable to establish loopback connection
at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:94) ~[?:?]
at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:61) ~[?:?]
at java.security.AccessController.doPrivileged(AccessController.java:554) ~[?:?]
at sun.nio.ch.PipeImpl.<init>(PipeImpl.java:171) ~[?:?]
at sun.nio.ch.SelectorProviderImpl.openPipe(SelectorProviderImpl.java:50) ~[?:?]
at java.nio.channels.Pipe.open(Pipe.java:155) ~[?:?]
at sun.nio.ch.WindowsSelectorImpl.<init>(WindowsSelectorImpl.java:127) ~[?:?]
at sun.nio.ch.WindowsSelectorProvider.openSelector(WindowsSelectorProvider.java:44) ~[?:?]
at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:178) ~[?:?]
at io.netty.channel.nio.NioEventLoop.<init>(NioEventLoop.java:146) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:138) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:37) ~[?:?]
at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:84) ~[?:?]
at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:58) ~[?:?]
at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:47) ~[?:?]
at io.netty.channel.MultithreadEventLoopGroup.<init>(MultithreadEventLoopGroup.java:59) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:78) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:73) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:60) ~[?:?]
at org.elasticsearch.transport.netty4.Netty4Transport.doStart(Netty4Transport.java:134) ~[?:?]
at org.elasticsearch.xpack.core.security.transport.netty4.SecurityNetty4Transport.doStart(SecurityNetty4Transport.java:81) ~[?:?]
at org.elasticsearch.xpack.security.transport.netty4.SecurityNetty4ServerTransport.doStart(SecurityNetty4ServerTransport.java:43) ~[?:?]
at org.elasticsearch.common.component.AbstractLifecycleComponent.start(AbstractLifecycleComponent.java:59) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.transport.TransportService.doStart(TransportService.java:230) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.common.component.AbstractLifecycleComponent.start(AbstractLifecycleComponent.java:59) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.node.Node.start(Node.java:695) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Bootstrap.start(Bootstrap.java:273) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:358) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:159) ~[elasticsearch-7.4.2.jar:7.4.2]
... 6 more
Caused by: java.net.BindException: Address already in use: connect
at sun.nio.ch.Net.connect0(Native Method) ~[?:?]
at sun.nio.ch.Net.connect(Net.java:493) ~[?:?]
at sun.nio.ch.Net.connect(Net.java:482) ~[?:?]
at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:732) ~[?:?]
at java.nio.channels.SocketChannel.open(SocketChannel.java:194) ~[?:?]
at sun.nio.ch.PipeImpl$Initializer$LoopbackConnector.run(PipeImpl.java:127) ~[?:?]
at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:76) ~[?:?]
at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:61) ~[?:?]
at java.security.AccessController.doPrivileged(AccessController.java:554) ~[?:?]
at sun.nio.ch.PipeImpl.<init>(PipeImpl.java:171) ~[?:?]
at sun.nio.ch.SelectorProviderImpl.openPipe(SelectorProviderImpl.java:50) ~[?:?]
at java.nio.channels.Pipe.open(Pipe.java:155) ~[?:?]
at sun.nio.ch.WindowsSelectorImpl.<init>(WindowsSelectorImpl.java:127) ~[?:?]
at sun.nio.ch.WindowsSelectorProvider.openSelector(WindowsSelectorProvider.java:44) ~[?:?]
at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:178) ~[?:?]
at io.netty.channel.nio.NioEventLoop.<init>(NioEventLoop.java:146) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:138) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:37) ~[?:?]
at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:84) ~[?:?]
at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:58) ~[?:?]
at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:47) ~[?:?]
at io.netty.channel.MultithreadEventLoopGroup.<init>(MultithreadEventLoopGroup.java:59) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:78) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:73) ~[?:?]
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:60) ~[?:?]
at org.elasticsearch.transport.netty4.Netty4Transport.doStart(Netty4Transport.java:134) ~[?:?]
at org.elasticsearch.xpack.core.security.transport.netty4.SecurityNetty4Transport.doStart(SecurityNetty4Transport.java:81) ~[?:?]
at org.elasticsearch.xpack.security.transport.netty4.SecurityNetty4ServerTransport.doStart(SecurityNetty4ServerTransport.java:43) ~[?:?]
at org.elasticsearch.common.component.AbstractLifecycleComponent.start(AbstractLifecycleComponent.java:59) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.transport.TransportService.doStart(TransportService.java:230) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.common.component.AbstractLifecycleComponent.start(AbstractLifecycleComponent.java:59) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.node.Node.start(Node.java:695) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Bootstrap.start(Bootstrap.java:273) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:358) ~[elasticsearch-7.4.2.jar:7.4.2]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:159) ~[elasticsearch-7.4.2.jar:7.4.2]
... 6 more
Below is the content of the elasticsearch.yml file.
# ======================== Elasticsearch Configuration =========================
#
# NOTE: Elasticsearch comes with reasonable defaults for most settings.
# Before you set out to tweak and tune the configuration, make sure you
# understand what are you trying to accomplish and the consequences.
#
# The primary way of configuring a node is via this file. This template lists
# the most important settings you may want to configure for a production cluster.
#
# Please consult the documentation for further information on configuration options:
# https://www.elastic.co/guide/en/elasticsearch/reference/index.html
#
# ---------------------------------- Cluster -----------------------------------
#
# Use a descriptive name for your cluster:
#
#cluster.name: my-application
#
# ------------------------------------ Node ------------------------------------
#
# Use a descriptive name for the node:
#
#node.name: node-1
#
# Add custom attributes to the node:
#
#node.attr.rack: r1
#
# ----------------------------------- Paths ------------------------------------
#
# Path to directory where to store the data (separate multiple locations by comma):
#
#path.data: /path/to/data
#
# Path to log files:
#
#path.logs: /path/to/logs
#
# ----------------------------------- Memory -----------------------------------
#
# Lock the memory on startup:
#
#bootstrap.memory_lock: true
#
# Make sure that the heap size is set to about half the memory available
# on the system and that the owner of the process is allowed to use this
# limit.
#
# Elasticsearch performs poorly when the system is swapping the memory.
#
# ---------------------------------- Network -----------------------------------
#
# Set the bind address to a specific IP (IPv4 or IPv6):
#
network.host: localhost
#
# Set a custom port for HTTP:
#
http.port: 19300
#
# For more information, consult the network module documentation.
#
# --------------------------------- Discovery ----------------------------------
#
# Pass an initial list of hosts to perform discovery when this node is started:
# The default list of hosts is ["127.0.0.1", "[::1]"]
#
#discovery.seed_hosts: ["host1", "host2"]
#
# Bootstrap the cluster using an initial set of master-eligible nodes:
#
#cluster.initial_master_nodes: ["node-1", "node-2"]
#
# For more information, consult the discovery and cluster formation module documentation.
#
# ---------------------------------- Gateway -----------------------------------
#
# Block initial recovery after a full cluster restart until N nodes are started:
#
#gateway.recover_after_nodes: 3
#
# For more information, consult the gateway module documentation.
#
# ---------------------------------- Various -----------------------------------
#
# Require explicit names when deleting indices:
#
#action.destructive_requires_name: true

Answer 1

The error message says that the port you configured is already in use.
Try starting up Elasticsearch using its default host and port configuration for both, the transport and http protocols by commenting out
# network.host: localhost
# http.port: 19300
Doing so should configure Elasticsearch to use localhost for both, the transport and http-protocols and the first available port in the range of 9200-9299 will be used for http while the first available port in the range of 9300-9399 will be used for transport.
BTW: Rather than specifying localhost you could/should use the special value "_local_" (see Elasticsearch Reference: Network Settings)