diff --git a/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/hotfix/ELNFixes.java b/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/hotfix/ELNFixes.java
index fb44178759fb842332566eabd7c34e8562140dd4..d625257e0091bef83ea569f1873d55543f7ff58c 100644
--- a/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/hotfix/ELNFixes.java
+++ b/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/hotfix/ELNFixes.java
@@ -23,6 +23,7 @@ public class ELNFixes {
         IApplicationServerInternalApi api = CommonServiceProvider.getApplicationServerApi();
         String sessionToken = api.loginAsSystem();
         storageValidationLevelFix(sessionToken, api);
+        operationLog.info("ELNFixes beforeUpgrade FINISH");
     }
 
     private static final String STORAGE_VALIDATION_LEVEL_PROPERTY_CODE = "$STORAGE.STORAGE_VALIDATION_LEVEL";
@@ -48,6 +49,9 @@ public class ELNFixes {
             }
         }
 
-        api.updateSamples(sessionToken, storageUpdates);
+        if (!storageUpdates.isEmpty()) {
+            api.updateSamples(sessionToken, storageUpdates);
+        }
+        operationLog.info("ELNFixes storageValidationLevelFix: " + storageUpdates.size());
     }
 }