diff --git a/entity/History_entity/entityfields/subject_details/valueProcess.js b/entity/History_entity/entityfields/subject_details/valueProcess.js
index 8fd762534b9ab8d337b4fc780d534caaac6cbce7..0a37a82465960cca3512490c0392c57dad354de7 100644
--- a/entity/History_entity/entityfields/subject_details/valueProcess.js
+++ b/entity/History_entity/entityfields/subject_details/valueProcess.js
@@ -2,6 +2,9 @@ import("system.vars");
 import("system.result");
 import("Keyword_lib");
 
-var kwdUtils;
-kwdUtils = new KeywordUtils();
-result.string(vars.get("$field.SUBJECT") + " (" + kwdUtils.getViewValue("HISTORY.MEDIUM", vars.get("$field.MEDIUM")) + ")");
\ No newline at end of file
+var kwdUtils, histMedium;
+histMedium = vars.get("$field.MEDIUM");
+if (histMedium){
+    kwdUtils = new KeywordUtils();
+    result.string(vars.get("$field.SUBJECT") + " (" + kwdUtils.getViewValue("HISTORY.MEDIUM", histMedium) + ")");
+}
\ No newline at end of file