explicitly set the language for elasticsearch script

extensions/elasticsearch/ActiveRecord.php

@@ -546,7 +546,8 @@ class ActiveRecord extends BaseActiveRecord
             }
             $data = Json::encode([
                 "script" => $script,
-                "params" => $counters
+                "params" => $counters,
+                "lang" => "groovy",
             ]);
             $bulk .= $action . "\n" . $data . "\n";
         }

extensions/elasticsearch/CHANGELOG.md

@@ -4,7 +4,7 @@ Yii Framework 2 elasticsearch extension Change Log
 2.0.1 under development
 -----------------------
 
-- no changes in this release.
+- Bug #5662: Elasticsearch AR updateCounters() now uses explicitly `groovy` script for updating making it compatible with ES >1.3.0 (cebe)
 
 
 2.0.0 October 12, 2014