diff --git a/src/main/kotlin/org/opensearch/replication/MappingNotAvailableException.kt b/src/main/kotlin/org/opensearch/replication/MappingNotAvailableException.kt
new file mode 100644
index 00000000..d4817478
--- /dev/null
+++ b/src/main/kotlin/org/opensearch/replication/MappingNotAvailableException.kt
@@ -0,0 +1,21 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.replication;
+
+import org.opensearch.OpenSearchException
+
+public class MappingNotAvailableException: OpenSearchException {
+
+    constructor(message: String, vararg args: Any) : super(message, *args)
+
+    constructor(message: String, cause: Throwable, vararg args: Any) : super(message,  cause, *args)
+}
diff --git a/src/main/kotlin/org/opensearch/replication/action/replay/TransportReplayChangesAction.kt b/src/main/kotlin/org/opensearch/replication/action/replay/TransportReplayChangesAction.kt
index 0a64584f..170a46ec 100644
--- a/src/main/kotlin/org/opensearch/replication/action/replay/TransportReplayChangesAction.kt
+++ b/src/main/kotlin/org/opensearch/replication/action/replay/TransportReplayChangesAction.kt
@@ -11,6 +11,7 @@
 
 package org.opensearch.replication.action.replay
 
+import org.opensearch.replication.MappingNotAvailableException
 import org.opensearch.replication.metadata.UpdateMetadataAction
 import org.opensearch.replication.metadata.UpdateMetadataRequest
 import org.opensearch.replication.metadata.checkIfIndexBlockedWithLevel
@@ -174,7 +175,12 @@ class TransportReplayChangesAction @Inject constructor(settings: Settings, trans
         val options = IndicesOptions.strictSingleIndexNoExpandForbidClosed()
         val getMappingsRequest = GetMappingsRequest().indices(leaderIndex).indicesOptions(options)
         val getMappingsResponse = remoteClient.suspending(remoteClient.admin().indices()::getMappings, injectSecurityContext = true)(getMappingsRequest)
-        val mappingSource = getMappingsResponse.mappings().get(leaderIndex).get(type).source().string()
+        val mappingSource = getMappingsResponse?.mappings()?.get(leaderIndex)?.get(type)?.source()?.string()
+        if (null == mappingSource) {
+            log.error("Mapping response: $getMappingsResponse")
+            throw MappingNotAvailableException("Mapping for the index $leaderIndex is not available")
+        }
+
 
         // This should use MappingUpdateAction but that uses PutMappingRequest internally and
         // PutMappingRequest#setConcreteIndex has a bug where it throws an NPE.This is fixed upstream in
diff --git a/src/main/kotlin/org/opensearch/replication/task/shard/TranslogSequencer.kt b/src/main/kotlin/org/opensearch/replication/task/shard/TranslogSequencer.kt
index cad3f0ef..63c192d8 100644
--- a/src/main/kotlin/org/opensearch/replication/task/shard/TranslogSequencer.kt
+++ b/src/main/kotlin/org/opensearch/replication/task/shard/TranslogSequencer.kt
@@ -11,6 +11,7 @@
 
 package org.opensearch.replication.task.shard
 
+import org.opensearch.replication.MappingNotAvailableException
 import org.opensearch.replication.ReplicationException
 import org.opensearch.replication.action.changes.GetChangesResponse
 import org.opensearch.replication.action.replay.ReplayChangesAction
@@ -28,6 +29,7 @@ import org.opensearch.common.logging.Loggers
 import org.opensearch.index.shard.ShardId
 import org.opensearch.index.translog.Translog
 import org.opensearch.tasks.TaskId
+import java.util.ArrayList
 import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.TimeUnit
 
@@ -65,7 +67,16 @@ class TranslogSequencer(scope: CoroutineScope, private val replicationMetadata:
                 replayRequest.parentTask = parentTaskId
                 launch {
                     var relativeStartNanos  = System.nanoTime()
-                    val replayResponse = client.suspendExecuteWithRetries(replicationMetadata, ReplayChangesAction.INSTANCE, replayRequest, log = log)
+                    val retryOnExceptions = ArrayList<Class<*>>()
+                    retryOnExceptions.add(MappingNotAvailableException::class.java)
+
+                    val replayResponse = client.suspendExecuteWithRetries(
+                        replicationMetadata,
+                        ReplayChangesAction.INSTANCE,
+                        replayRequest,
+                        log = log,
+                        retryOn = retryOnExceptions
+                    )
                     if (replayResponse.shardInfo.failed > 0) {
                         replayResponse.shardInfo.failures.forEachIndexed { i, failure ->
                             log.error("Failed replaying changes. Failure:$i:$failure")