diff --git a/includes/classes/Command.php b/includes/classes/Command.php
index b49dfc50f8..e5d9f6e25d 100644
--- a/includes/classes/Command.php
+++ b/includes/classes/Command.php
@@ -290,7 +290,7 @@ private function put_mapping_helper( $args, $assoc_args ) {
 							sprintf(
 								/* translators: Error message */
 								esc_html__( 'Mapping failed: %s', 'elasticpress' ),
-								$result->get_error_message()
+								Utils\get_elasticsearch_error_reason( $result->get_error_message() )
 							)
 						);
 					}
@@ -330,7 +330,7 @@ private function put_mapping_helper( $args, $assoc_args ) {
 						sprintf(
 							/* translators: Error message */
 							esc_html__( 'Mapping failed: %s', 'elasticpress' ),
-							$result->get_error_message()
+							Utils\get_elasticsearch_error_reason( $result->get_error_message() )
 						)
 					);
 				}
@@ -371,7 +371,7 @@ private function put_mapping_helper( $args, $assoc_args ) {
 					sprintf(
 						/* translators: Error message */
 						esc_html__( 'Mapping failed: %s', 'elasticpress' ),
-						$result->get_error_message()
+						Utils\get_elasticsearch_error_reason( $result->get_error_message() )
 					)
 				);
 			}
diff --git a/includes/classes/IndexHelper.php b/includes/classes/IndexHelper.php
index 6dee7f4d7c..cbb6718af3 100644
--- a/includes/classes/IndexHelper.php
+++ b/includes/classes/IndexHelper.php
@@ -1337,8 +1337,11 @@ protected function on_error_update_and_clean( $error, $context = 'sync' ) {
 
 		switch ( $context ) {
 			case 'mapping':
-				/* translators: Error message */
-				$message  = sprintf( esc_html__( 'Mapping failed: %s', 'elasticpress' ), $error['message'] );
+				$message = sprintf(
+					/* translators: Error message */
+					esc_html__( 'Mapping failed: %s', 'elasticpress' ),
+					Utils\get_elasticsearch_error_reason( $error['message'] )
+				);
 				$message .= "\n";
 				$message .= esc_html__( 'Mapping has failed, which will cause ElasticPress search results to be incorrect. Please click `Delete all Data and Start a Fresh Sync` to retry mapping.', 'elasticpress' );
 				break;
diff --git a/includes/classes/StatusReport/FailedQueries.php b/includes/classes/StatusReport/FailedQueries.php
index 799a1911cf..0a6868b255 100644
--- a/includes/classes/StatusReport/FailedQueries.php
+++ b/includes/classes/StatusReport/FailedQueries.php
@@ -146,15 +146,7 @@ protected function maybe_clear_logs() {
 	 * @return array The error in index 0, solution in index 1
 	 */
 	public function analyze_log( $log ) {
-		$error = '';
-
-		if ( ! empty( $log['result']['error'] ) && ! empty( $log['result']['error']['root_cause'][0]['reason'] ) ) {
-			$error = $log['result']['error']['root_cause'][0]['reason'];
-		}
-
-		if ( ! empty( $log['result']['errors'] ) && ! empty( $log['result']['items'] ) && ! empty( $log['result']['items'][0]['index']['error']['reason'] ) ) {
-			$error = $log['result']['items'][0]['index']['error']['reason'];
-		}
+		$error = Utils\get_elasticsearch_error_reason( $log );
 
 		$solution = ( ! empty( $error ) ) ?
 			$this->maybe_suggest_solution_for_es( $error ) :
diff --git a/includes/utils.php b/includes/utils.php
index 9bb93c2a2d..e9aed09df8 100644
--- a/includes/utils.php
+++ b/includes/utils.php
@@ -787,3 +787,34 @@ function generate_request_id() : string {
 	 */
 	return apply_filters( 'ep_request_id', get_request_id_base() . $uuid );
 }
+
+/**
+ * Given an Elasticsearch response, try to find an error message.
+ *
+ * @since 4.6.0
+ * @param mixed $response The Elasticsearch response
+ * @return string
+ */
+function get_elasticsearch_error_reason( $response ) : string {
+	if ( is_string( $response ) ) {
+		return $response;
+	}
+
+	if ( ! is_array( $response ) ) {
+		return var_export( $response, true ); // phpcs:ignore WordPress.PHP.DevelopmentFunctions
+	}
+
+	if ( ! empty( $response['reason'] ) ) {
+		return $response['reason'];
+	}
+
+	if ( ! empty( $response['result']['error'] ) && ! empty( $response['result']['error']['root_cause'][0]['reason'] ) ) {
+		return $response['result']['error']['root_cause'][0]['reason'];
+	}
+
+	if ( ! empty( $response['result']['errors'] ) && ! empty( $response['result']['items'] ) && ! empty( $response['result']['items'][0]['index']['error']['reason'] ) ) {
+		return $response['result']['items'][0]['index']['error']['reason'];
+	}
+
+	return '';
+}
diff --git a/tests/php/TestUtils.php b/tests/php/TestUtils.php
index 6d19b2253d..211159cd04 100644
--- a/tests/php/TestUtils.php
+++ b/tests/php/TestUtils.php
@@ -329,4 +329,64 @@ public function testGetPostMapCapabilities() {
 
 		$this->assertSame( $expected, Utils\get_post_map_capabilities() );
 	}
+
+	/**
+	 * Test the `get_elasticsearch_error_reason` function
+	 *
+	 * @since 4.6.0
+	 */
+	public function testGetElasticsearchErrorReason() {
+		// Strings should be returned without any change
+		$this->assertSame( 'Some message', Utils\get_elasticsearch_error_reason( 'Some message' ) );
+
+		// Objects will be returned after passing through var_export()
+		$object = (object) [ 'attribute' => 'this will be an object' ];
+		$return = Utils\get_elasticsearch_error_reason( $object );
+		$this->assertIsString( $return );
+		$this->assertStringContainsString( 'attribute', $return );
+		$this->assertStringContainsString( 'this will be an object', $return );
+
+		// `reason` in the array root
+		$reason_root = [ 'reason' => 'Error reason' ];
+		$this->assertSame( 'Error reason', Utils\get_elasticsearch_error_reason( $reason_root ) );
+
+		// array with `error`
+		$reason_in_single_error_array = [
+			'result' => [
+				'error' => [
+					'root_cause' => [
+						[
+							'reason' => 'Error reason',
+						],
+					],
+				],
+			],
+		];
+		$this->assertSame( 'Error reason', Utils\get_elasticsearch_error_reason( $reason_in_single_error_array ) );
+
+		// array with `errors`
+		$reason_in_errors_array = [
+			'result' => [
+				'errors' => [
+					'some error',
+				],
+				'items'  => [
+					[
+						'index' => [
+							'error' => [
+								'reason' => 'Error reason',
+							],
+						],
+					],
+				],
+			],
+		];
+		$this->assertSame( 'Error reason', Utils\get_elasticsearch_error_reason( $reason_in_errors_array ) );
+
+		// For something that is an array but does not have a format of an error, return an empty string
+		$not_an_error = [
+			'results' => [ 1, 2, 3 ],
+		];
+		$this->assertSame( '', Utils\get_elasticsearch_error_reason( $not_an_error ) );
+	}
 }