diff --git a/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/ETLService.java b/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/ETLService.java
index 120d5a954858fc5dccfcdc57015aeb0b682ac22e..eac128965081bb3990adfbf1d745c201ced8a9ea 100644
--- a/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/ETLService.java
+++ b/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/ETLService.java
@@ -1606,7 +1606,10 @@ public class ETLService extends AbstractCommonServer<IETLLIMSService> implements
         dataBO.loadByCode(dataSetCode);
         DataPE data = dataBO.getData();
 
-        daoFactory.getPostRegistrationDAO().removeDataSet(data);
+        if (data != null)
+        {
+            daoFactory.getPostRegistrationDAO().removeDataSet(data);
+        }
     }
 
     public List<ExternalData> listDataSetsForPostRegistration(String sessionToken,
diff --git a/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/dataaccess/db/PostRegistrationDAO.java b/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/dataaccess/db/PostRegistrationDAO.java
index 1a4a3d8d23ba2a2857cf0e527c88e4b05c36a097..ee6ccd0a1efb801beae523234991c8a46764ace6 100644
--- a/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/dataaccess/db/PostRegistrationDAO.java
+++ b/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/dataaccess/db/PostRegistrationDAO.java
@@ -58,8 +58,9 @@ public class PostRegistrationDAO extends AbstractGenericEntityDAO<PostRegistrati
         final PostRegistrationPE pr = (PostRegistrationPE) criteria.uniqueResult();
         if (operationLog.isDebugEnabled())
         {
-            operationLog.debug(String.format(
-                    "Following experiment '%s' has been found for dataSet '%s'.", pr, dataSet));
+            if (pr == null)
+                operationLog.debug(String.format(
+                        "Post registration entry has been found for dataSet '%s'.", dataSet));
         }
         return pr;
     }