diff --git a/app/controllers/upgrade_controller.rb b/app/controllers/upgrade_controller.rb
index 0b0f431..679c74e 100644
--- a/app/controllers/upgrade_controller.rb
+++ b/app/controllers/upgrade_controller.rb
@@ -52,8 +52,8 @@ class UpgradeController < ApplicationController
 				}
 			end
 			text = {"en" => "", "zh_tw" => ""}
-			text["en"] = smart_convertor(b.text_translations["en"])
-			text["zh_tw"] = smart_convertor(b.text_translations["zh_tw"])
+			text["en"] = smart_convertor(b.text_translations["en"]) if !b.text_translations["en"].nil?
+			text["zh_tw"] = smart_convertor(b.text_translations["zh_tw"]) if !b.text_translations["en"].nil?
 
 			{
 				"id" => b.id.to_s,