diff --git a/datastore_server/source/java/ch/systemsx/cisd/openbis/dss/client/api/v1/impl/DssComponent.java b/datastore_server/source/java/ch/systemsx/cisd/openbis/dss/client/api/v1/impl/DssComponent.java
index 40fe58318fe49cb25b6d22f5268a78e81f8720aa..a955c86eeda16d95deafaa2d34dd45256f17c965 100644
--- a/datastore_server/source/java/ch/systemsx/cisd/openbis/dss/client/api/v1/impl/DssComponent.java
+++ b/datastore_server/source/java/ch/systemsx/cisd/openbis/dss/client/api/v1/impl/DssComponent.java
@@ -656,7 +656,7 @@ class AuthenticatedState extends AbstractDssComponentState
         {
             // ignore the error here since, if it is significant, it will appear again in
             // validation.
-            return new HashMap<String, String>();
+            return Collections.emptyMap();
         }
 
         try
@@ -667,7 +667,7 @@ class AuthenticatedState extends AbstractDssComponentState
             System.err.println("Could not run metadata extraction script: ");
             System.err.println(runner.getScriptString());
             t.printStackTrace(System.err);
-            return new HashMap<String, String>();
+            return Collections.emptyMap();
         }
     }
 
diff --git a/datastore_server/source/java/ch/systemsx/cisd/openbis/dss/generic/shared/api/v1/validation/ValidationScriptRunner.java b/datastore_server/source/java/ch/systemsx/cisd/openbis/dss/generic/shared/api/v1/validation/ValidationScriptRunner.java
index dcc5123adf9f57e62211338c2c5a5b50d68adaed..65b52ba2fb15004e316fa20316b77061ccb06d0c 100644
--- a/datastore_server/source/java/ch/systemsx/cisd/openbis/dss/generic/shared/api/v1/validation/ValidationScriptRunner.java
+++ b/datastore_server/source/java/ch/systemsx/cisd/openbis/dss/generic/shared/api/v1/validation/ValidationScriptRunner.java
@@ -143,6 +143,11 @@ public class ValidationScriptRunner
     {
         Map<String, String> metadata = new HashMap<String, String>();
         PyFunction function = tryJythonFunction(EXTRACT_METADATA_FUNCTION_NAME);
+        if (function == null)
+        {
+            return Collections.emptyMap();
+        }
+
         PyObject result = function.__call__(Py.java2py(dataSetFile));
         if (null != result)
         {