diff --git a/app/workers/score_calculator_worker.rb b/app/workers/score_calculator_worker.rb
index 5effb8dfb14346562a0d7eca21a695c05dd5345b..308f6c824517a931a201d0ce257af4cb8f4a6866 100644
--- a/app/workers/score_calculator_worker.rb
+++ b/app/workers/score_calculator_worker.rb
@@ -4,26 +4,28 @@ class ScoreCalculatorWorker
   include RepositoriesProxy
 
   def perform(rid)
-    weights = {"thumbnail": 40, "likes": 20, "views": 10, "description": 30}
-
     object = learning_object_repository.find(rid)
 
-    score = 0
+    unless object.blank?
+      weights = {"thumbnail": 40, "likes": 20, "views": 10, "description": 30}
+
+      score = 0
 
-    # 40 points if it has thumbnail
-    score += weights[:thumbnail] unless object.thumbnail.empty?
+      # 40 points if it has thumbnail
+      score += weights[:thumbnail] unless object.thumbnail.blank?
 
-    # 1 point per like
-    likes = learning_object_repository.count_likes(object)
-    score += (likes / learning_object_repository.max_likes)*weights[:likes]  unless likes < 1
+      # 1 point per like
+      likes = learning_object_repository.count_likes(object)
+      score += (likes / learning_object_repository.max_likes)*weights[:likes]  unless likes < 1
 
-    # 1 point per view
-    views = learning_object_repository.count_views(object)
-    score += (views / learning_object_repository.max_views)*weights[:views] unless views < 1
+      # 1 point per view
+      views = learning_object_repository.count_views(object)
+      score += (views / learning_object_repository.max_views)*weights[:views] unless views < 1
 
-    # 30 points if it has description
-    score += weights[:description] unless object.description.empty?
+      # 30 points if it has description
+      score += weights[:description] unless object.description.blank?
 
-    learning_object_repository.update_property(object, 'score', score)
+      learning_object_repository.update_property(object, 'score', score)
+    end
   end
 end
diff --git a/config/sidekiq.yml b/config/sidekiq.yml
index fb9ad31f75c5d9b474f11d56d2ca14f553ddd064..dcbb188e02836756f055dd619b2fc061347b9cbb 100644
--- a/config/sidekiq.yml
+++ b/config/sidekiq.yml
@@ -14,7 +14,7 @@
 # :daemon: true
 
 development: &development
-  concurrency: 5
+  :concurrency: 8
   host: localhost
   port: 6379