rs.stepDown() Error

MongoDB Enterprise replicationTest:PRIMARY> rs.stepDown()
2019-05-26T04:59:59.268+0000 E QUERY [thread1] Error: error doing query: failed: network error while attempting to run command ‘replSetStepDown’ on host ‘192.168.103.100:27010’ :
DB.prototype.runCommand@src/mongo/shell/db.js:168:1
DB.prototype.adminCommand@src/mongo/shell/db.js:186:16
rs.stepDown@src/mongo/shell/utils.js:1352:12
@(shell):1:1
2019-05-26T04:59:59.269+0000 I NETWORK [thread1] Marking host 192.168.103.100:27010 as failed :: caused by :: Location40657: Last known master host cannot be reached

If you want to step down the primary other two secondaries should be up
What was the rs.status() before you issued step down

MongoDB Enterprise replicationTest:PRIMARY> rs.status()
{
    "set" : "replicationTest",
    "date" : ISODate("2019-05-26T15:15:14.283Z"),
    "myState" : 1,
    "term" : NumberLong(27),
    "syncingTo" : "",
    "syncSourceHost" : "",
    "syncSourceId" : -1,
    "heartbeatIntervalMillis" : NumberLong(2000),
    "optimes" : {
            "lastCommittedOpTime" : {
                    "ts" : Timestamp(1558883707, 1),
                    "t" : NumberLong(27)
            },
            "readConcernMajorityOpTime" : {
                    "ts" : Timestamp(1558883707, 1),
                    "t" : NumberLong(27)
            },
            "appliedOpTime" : {
                    "ts" : Timestamp(1558883707, 1),
                    "t" : NumberLong(27)
            },
            "durableOpTime" : {
                    "ts" : Timestamp(1558883707, 1),
                    "t" : NumberLong(27)
            }
    },
    "members" : [
            {
                    "_id" : 0,
                    "name" : "192.168.103.100:27010",
                    "health" : 1,
                    "state" : 1,
                    "stateStr" : "PRIMARY",
                    "uptime" : 69,
                    "optime" : {
                            "ts" : Timestamp(1558883707, 1),
                            "t" : NumberLong(27)
                    },
                    "optimeDate" : ISODate("2019-05-26T15:15:07Z"),
                    "syncingTo" : "",
                    "syncSourceHost" : "",
                    "syncSourceId" : -1,
                    "infoMessage" : "could not find member to sync from",
                    "electionTime" : Timestamp(1558883658, 1),
                    "electionDate" : ISODate("2019-05-26T15:14:18Z"),
                    "configVersion" : 11,
                    "self" : true,
                    "lastHeartbeatMessage" : ""
            },
            {
                    "_id" : 1,
                    "name" : "192.168.103.100:27011",
                    "health" : 1,
                    "state" : 2,
                    "stateStr" : "SECONDARY",
                    "uptime" : 62,
                    "optime" : {
                            "ts" : Timestamp(1558883707, 1),
                            "t" : NumberLong(27)
                    },
                    "optimeDurable" : {
                            "ts" : Timestamp(1558883707, 1),
                            "t" : NumberLong(27)
                    },
                    "optimeDate" : ISODate("2019-05-26T15:15:07Z"),
                    "optimeDurableDate" : ISODate("2019-05-26T15:15:07Z"),
                    "lastHeartbeat" : ISODate("2019-05-26T15:15:12.424Z"),
                    "lastHeartbeatRecv" : ISODate("2019-05-26T15:15:14.126Z"),
                    "pingMs" : NumberLong(0),
                    "lastHeartbeatMessage" : "",
                    "syncingTo" : "192.168.103.100:27010",
                    "syncSourceHost" : "192.168.103.100:27010",
                    "syncSourceId" : 0,
                    "infoMessage" : "",
                    "configVersion" : 11
            },
            {
                    "_id" : 2,
                    "name" : "192.168.103.100:27012",
                    "health" : 1,
                    "state" : 2,
                    "stateStr" : "SECONDARY",
                    "uptime" : 58,
                    "optime" : {
                            "ts" : Timestamp(1558883707, 1),
                            "t" : NumberLong(27)
                    },
                    "optimeDurable" : {
                            "ts" : Timestamp(1558883707, 1),
                            "t" : NumberLong(27)
                    },
                    "optimeDate" : ISODate("2019-05-26T15:15:07Z"),
                    "optimeDurableDate" : ISODate("2019-05-26T15:15:07Z"),
                    "lastHeartbeat" : ISODate("2019-05-26T15:15:12.424Z"),
                    "lastHeartbeatRecv" : ISODate("2019-05-26T15:15:14.200Z"),
                    "pingMs" : NumberLong(0),
                    "lastHeartbeatMessage" : "",
                    "syncingTo" : "192.168.103.100:27010",
                    "syncSourceHost" : "192.168.103.100:27010",
                    "syncSourceId" : 0,
                    "infoMessage" : "",
                    "configVersion" : 11
            },
            {
                    "_id" : 3,
                    "name" : "192.168.103.100:27013",
                    "health" : 0,
                    "state" : 6,
                    "stateStr" : "(not reachable/healthy)",
                    "uptime" : 0,
                    "optime" : {
                            "ts" : Timestamp(0, 0),
                            "t" : NumberLong(-1)
                    },
                    "optimeDurable" : {
                            "ts" : Timestamp(0, 0),
                            "t" : NumberLong(-1)
                    },
                    "optimeDate" : ISODate("1970-01-01T00:00:00Z"),
                    "optimeDurableDate" : ISODate("1970-01-01T00:00:00Z"),
                    "lastHeartbeat" : ISODate("2019-05-26T15:15:12.503Z"),
                    "lastHeartbeatRecv" : ISODate("1970-01-01T00:00:00Z"),
                    "pingMs" : NumberLong(0),
                    "lastHeartbeatMessage" : "",
                    "authenticated" : false,
                    "syncingTo" : "",
                    "syncSourceHost" : "",
                    "syncSourceId" : -1,
                    "infoMessage" : "",
                    "configVersion" : -1
            }
    ],
    "ok" : 1,
    "operationTime" : Timestamp(1558883707, 1),
    "$clusterTime" : {
            "clusterTime" : Timestamp(1558883707, 1),
            "signature" : {
                    "hash" : BinData(0,"sD2UjQNNglBz2NZuD54efl5RBmU="),
                    "keyId" : NumberLong("6695051280781410305")
            }
    }
}

It says instance on 27013 is not reachable/healthy
When you setup 4 node cluster were all the nodes working properly?(primary+ 3 secondaries)
When you stepdown primary other secondaries will poll among themselves and decide on new primary
Since one of the node is not healthy and not in sync with primary it is unable to stepdown

Please check this link

https://docs.mongodb.com/manual/reference/method/rs.stepDown/

vagrant@m103:~$ ps -ef | grep mongod
vagrant   1448     1  2 16:37 ?        00:01:12 mongod -f mongodTest/replication/repl-node1/etc/mongod.cfg
vagrant   1528     1  2 16:37 ?        00:01:11 mongod -f mongodTest/replication/repl-node2/etc/mongod.cfg
vagrant   1610     1  2 16:37 ?        00:01:11 mongod -f mongodTest/replication/repl-node3/etc/mongod.cfg
vagrant   1723     1  1 16:38 ?        00:00:36 mongod -f mongodTest/replication/repl-node4/etc/mongod.cfg
vagrant   6951  1418  0 17:32 pts/0    00:00:00 grep --color=auto mongod

I started all the nodes, the fourth node is hidden, is this the problem?@Ramachandra_37567