Hello Everyone,
Could you please guide me w.r.t to below error message 
, -Dlog4j2.disable.jmx=true, -Djava.io.tmpdir=/tmp/elasticsearch.AY33SMYc, -XX:+HeapDumpOnOutOfMemoryError, -XX:HeapDumpPath=/var/lib/elasticsearch, -XX:+PrintGCDetails, -XX:+PrintGCDateStamps, -XX:+PrintTenuringDistribution, -XX:+PrintGCApplicationStoppedTime, -Xloggc:/var/log/elasticsearch/gc.log, -XX:+UseGCLogFileRotation, -XX:NumberOfGCLogFiles=32, -XX:GCLogFileSize=64m, -Des.path.home=/usr/share/elasticsearch, -Des.path.conf=/etc/elasticsearch]
[2018-09-11T01:35:05,929][ERROR][o.e.b.Bootstrap ] Exception
java.lang.IllegalStateException: failed to load plugin class [org.elasticsearch.xpack.core.XPackPlugin]
at org.elasticsearch.plugins.PluginsService.loadPlugin(PluginsService.java:563) ~[elasticsearch-6.2.2.jar:6.2.2]
at org.elasticsearch.plugins.PluginsService.loadBundle(PluginsService.java:505) ~
... 15 more
Caused by: org.elasticsearch.ElasticsearchException: failed to initialize a TrustManagerFactory
at org.elasticsearch.xpack.core.ssl.StoreTrustConfig.createTrustManager(StoreTrustConfig.java:72) ~[?:?]
at org.elasticsearch.xpack.core.ssl.SSLService.createSslContext(SSLService.java:412) ~[?:?]
at java.util.HashMap.computeIfAbsent(HashMap.java:1127) ~[?:1.8.0_181]
at org.elasticsearch.xpack.core.ssl.SSLService.loadSSLConfigurations(SSLService.java:464) ~[?:?]
at org.elasticsearch.xpack.core.ssl.SSLService.(SSLService.java:91) ~[?:?]
at org.elasticsearch.xpack.core.XPackPlugin.(XPackPlugin.java:127) ~[?:?]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:?]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[?:?]
at
Caused by: java.security.AccessControlException: access denied ("java.io.FilePermission" "/usr/share/elasticsearch/config/certs/elastic-certificates.p12" "read")
at java.security.AccessControlContext.checkPermission(AccessControlContext.java:472)
[2018-09-11T01:35:05,940][WARN ][o.e.b.ElasticsearchUncaughtExceptionHandler] [SPLAWSDOPS06] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.IllegalStateException: failed to load plugin class [org.elasticsearch.xpack.core.XPackPlugin]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:125) ~
at org.elasticsearch.cli.Command.main(Command.java:90) ~[elasticsearch-cli-6.2.2.jar:6.2.2]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:92) ~[elasticsearch-6.2.2.jar:6.2.2]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:85) ~[elasticsearch-6.2.2.jar:6.2.2]
Caused by: java.lang.IllegalStateException: failed to load plugin class [org.elasticsearch.xpack.core.XPackPlugin]
at org.elasticsearch.plugins.PluginsService.loadPlugin(PluginsService.java:563) ~
Caused by: org.elasticsearch.ElasticsearchException: failed to initialize a TrustManagerFactory
at org.elasticsearch.xpack.core.ssl.StoreTrustConfig.createTrustManager(StoreTrustConfig.java:72) ~[?:?]
at org.elasticsearch.xpack.core.ssl.SSLService.createSslContext(SSLService.java:412) ~[?:?]
at java.util.HashMap.computeIfAbsent(HashMap.java:1127) ~[?:1.8.0_181]
at org.elasticsearch.xpack.core.ssl.SSLService.loadSSLConfigurations(SSLService.java:464) ~[?:?]
at org.elasticsearch.xpack.core.ssl.SSLService.(SSLService.java:91) ~[?:?]
at org.elasticsearch.xpack.core.XPackPlugin.(XPackPlugin.java:127) ~[?:?]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:?]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[?:?]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[?:?]
at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[?:1.8.0_181]
at org.elasticsearch.plugins.PluginsService.loadPlugin(PluginsService.java:554) ~[elasticsearch-6.2.2.jar:6.2.2]
at org.elasticsearch.plugins.PluginsService.loadBundle(PluginsService.java:505) ~[elasticsearch-6.2.2.jar:6.2.2]
at org.elasticsearch.plugins.PluginsService.loadBundles(PluginsService.java:422) ~[elasticsearch-6.2.2.jar:6.2.2]
at org.elasticsearch.plugins.PluginsService.(PluginsService.java:146) ~[elasticsearch-6.2.2.jar:6.2.2]
at org.elasticsearch.node.Node.(Node.java:303) ~[elasticsearch-6.2.2.jar:6.2.2]
at org.elasticsearch.node.Node.(Node.java:246) ~[elasticsearch-6.2.2.jar:6.2.2]
at org.elasticsearch.bootstrap.Bootstrap$5.(Bootstrap.java:213) ~[elasticsearch-6.2.2.jar:6.2.2]
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:213) ~[elasticsearch-6.2.2.jar:6.2.2]
Caused by: java.security.AccessControlException: access denied ("java.io.FilePermission" "/usr/share/elasticsearch/config/certs/elastic-certificates.p12" "read")
at java.security.AccessControlContext.checkPermission(AccessControlContext.java:472) ~[?:1.8.0_181]
at java.security.AccessController.checkPermission(AccessController.java:884) ~[?:1.8.0_181]
at java.lang.SecurityManager.checkPermission(SecurityManager.java:549) ~[?:1.8.0_181]
at java.lang.SecurityManager.checkRead(SecurityManager.java:888) ~[?:1.8.0_181]
at sun.nio.fs.UnixChannelFactory.open(UnixChannelFactory.java:245) ~[?:?]
at sun.nio.fs.UnixChannelFactory.newFileChannel(UnixChannelFactory.java:136) ~[?:?]
at sun.nio.fs.UnixChannelFactory.newFileChannel(UnixChannelFactory.java:148) ~[?:?]
at sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:212) ~ at java.util.HashMap.computeIfAbsent(HashMap.java:1127) ~[?:1.8.0_181]
at org.elasticsearch.xpack.core.ssl.SSLService.loadSSLConfigurations(SSLService.java:464) ~[?:?]
at org.elasticsearch.xpack.core.ssl.SSLService.(SSLService.java:91) ~[?:?]
at org.elasticsearch.xpack.core.XPackPlugin.(XPackPlugin.java:127) ~[?:?]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:?]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[?:?]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[?:?]