Hi David,
I didnt got the Login prompt .Just FYI,I dont have xpack.security.enabled in either of file(kibana.yml & elasticsearch.yml) since its defaults to TRUE.I dont see any error log in Elasticsearch.log.PFA logs
2019-07-12T15:36:24,979][INFO ][o.e.n.Node ] initializing ...
[2019-07-12T15:36:25,092][INFO ][o.e.e.NodeEnvironment ] [vdS_UIV] using [1] data paths, mounts [[/ (rootfs)]], net usable_space [43gb], net total_space [49.9gb], spins? [unknown], types [rootfs]
[2019-07-12T15:36:25,092][INFO ][o.e.e.NodeEnvironment ] [vdS_UIV] heap size [1.9gb], compressed ordinary object pointers [true]
[2019-07-12T15:36:25,116][INFO ][o.e.n.Node ] node name [vdS_UIV] derived from node ID [vdS_UIV1Tkq_GB9tpvbJrA]; set [node.name] to override
[2019-07-12T15:36:25,117][INFO ][o.e.n.Node ] version[5.6.15], pid[2084], build[fe7575a/2019-02-13T16:21:45.880Z], OS[Linux/3.10.0-693.el7.x86_64/amd64], JVM[Oracle Corporation/Java HotSpot(TM) 64-Bit Server VM/1.8.0_131/25.131-b11]
[2019-07-12T15:36:25,117][INFO ][o.e.n.Node ] JVM arguments [-Xms2g, -Xmx2g, -XX:+UseConcMarkSweepGC, -XX:CMSInitiatingOccupancyFraction=75, -XX:+UseCMSInitiatingOccupancyOnly, -XX:+AlwaysPreTouch, -Xss1m, -Djava.awt.headless=true, -Dfile.encoding=UTF-8, -Djna.nosys=true, -Djdk.io.permissionsUseCanonicalPath=true, -Dio.netty.noUnsafe=true, -Dio.netty.noKeySetOptimization=true, -Dio.netty.recycler.maxCapacityPerThread=0, -Dlog4j.shutdownHookEnabled=false, -Dlog4j2.disable.jmx=true, -Dlog4j.skipJansi=true, -XX:+HeapDumpOnOutOfMemoryError, -Des.path.home=/usr/share/elasticsearch]
[2019-07-12T15:36:27,083][INFO ][o.e.p.PluginsService ] [vdS_UIV] loaded module [aggs-matrix-stats]
[2019-07-12T15:36:27,083][INFO ][o.e.p.PluginsService ] [vdS_UIV] loaded module [ingest-common]
[2019-07-12T15:36:27,083][INFO ][o.e.p.PluginsService ] [vdS_UIV] loaded module [lang-expression]
[2019-07-12T15:36:27,083][INFO ][o.e.p.PluginsService ] [vdS_UIV] loaded module [lang-groovy]
[2019-07-12T15:36:27,083][INFO ][o.e.p.PluginsService ] [vdS_UIV] loaded module [lang-mustache]
[2019-07-12T15:36:27,083][INFO ][o.e.p.PluginsService ] [vdS_UIV] loaded module [lang-painless]
[2019-07-12T15:36:27,083][INFO ][o.e.p.PluginsService ] [vdS_UIV] loaded module [parent-join]
[2019-07-12T15:36:27,083][INFO ][o.e.p.PluginsService ] [vdS_UIV] loaded module [percolator]
[2019-07-12T15:36:27,083][INFO ][o.e.p.PluginsService ] [vdS_UIV] loaded module [reindex]
[2019-07-12T15:36:27,083][INFO ][o.e.p.PluginsService ] [vdS_UIV] loaded module [transport-netty3]
[2019-07-12T15:36:27,083][INFO ][o.e.p.PluginsService ] [vdS_UIV] loaded module [transport-netty4]
[2019-07-12T15:36:27,084][INFO ][o.e.p.PluginsService ] [vdS_UIV] loaded plugin [x-pack]
[2019-07-12T15:36:29,618][DEBUG][o.e.a.ActionModule ] Using REST wrapper from plugin org.elasticsearch.xpack.XPackPlugin
[2019-07-12T15:36:30,756][INFO ][o.e.x.m.j.p.l.CppLogMessageHandler] [controller/2245] [Main.cc@128] controller (64 bit): Version 5.6.15 (Build bbd204010bbfc5) Copyright (c) 2019 Elasticsearch BV
[2019-07-12T15:36:30,780][INFO ][o.e.d.DiscoveryModule ] [vdS_UIV] using discovery type [zen]
[2019-07-12T15:36:32,034][INFO ][o.e.n.Node ] initialized
[2019-07-12T15:36:32,034][INFO ][o.e.n.Node ] [vdS_UIV] starting ...
[2019-07-12T15:36:32,362][INFO ][o.e.t.TransportService ] [vdS_UIV] publish_address {127.0.0.1:9300}, bound_addresses {[::1]:9300}, {127.0.0.1:9300}
[2019-07-12T15:36:35,523][INFO ][o.e.c.s.ClusterService ] [vdS_UIV] new_master {vdS_UIV}{vdS_UIV1Tkq_GB9tpvbJrA}{bERGY0SkTGaSa3WJcCWuMQ}{127.0.0.1}{127.0.0.1:9300}{ml.max_open_jobs=10, ml.enabled=true}, reason: zen-disco-elected-as-master ([0] nodes joined)
[2019-07-12T15:36:35,556][INFO ][o.e.x.s.t.n.SecurityNetty4HttpServerTransport] [vdS_UIV] publish_address {127.0.0.1:9200}, bound_addresses {[::1]:9200}, {127.0.0.1:9200}
[2019-07-12T15:36:35,556][INFO ][o.e.n.Node ] [vdS_UIV] started
[2019-07-12T15:36:36,334][INFO ][o.e.l.LicenseService ] [vdS_UIV] license [b82f52f6-1e8f-4f94-978f-de68012f02f7] mode [basic] - valid
[2019-07-12T15:36:36,348][INFO ][o.e.g.GatewayService ] [vdS_UIV] recovered [5] indices into cluster_state
[2019-07-12T15:36:36,725][INFO ][o.e.c.r.a.AllocationService] [vdS_UIV] Cluster health status changed from [RED] to [YELLOW] (reason: [shards started [[.security][0], [.monitoring-es-6-2019.07.12][0], [.watches][0], [.kibana][0]] ...]).
[2019-07-12T15:36:36,756][WARN ][o.e.x.s.a.s.m.NativeRoleMappingStore] [vdS_UIV] Failed to clear cache for realms []
[2019-07-12T15:39:13,766][INFO ][o.e.c.m.MetaDataMappingService] [vdS_UIV] [.kibana/6ymd9ycaRCewde5FPy_6iA] update_mapping [config]