diff --git a/openbis/source/java/ch/systemsx/cisd/openbis/generic/shared/dto/AtomicEntityOperationDetails.java b/openbis/source/java/ch/systemsx/cisd/openbis/generic/shared/dto/AtomicEntityOperationDetails.java
index 237b95f7c6511c4061bebbd28fdac1f98bbc01e5..d3a452b50077391a52d9fb0ef0531ae2a5e1646c 100644
--- a/openbis/source/java/ch/systemsx/cisd/openbis/generic/shared/dto/AtomicEntityOperationDetails.java
+++ b/openbis/source/java/ch/systemsx/cisd/openbis/generic/shared/dto/AtomicEntityOperationDetails.java
@@ -289,16 +289,18 @@ public class AtomicEntityOperationDetails implements Serializable
         {
             object = ((Map<?, ?>) object).entrySet();
         }
-        if (object instanceof Collection<?> == false)
+        if (object instanceof Collection<?>)
         {
-            builder.append(name, object);
-        }
-        Collection<?> collection = (Collection<?>) object;
-        if (collection.isEmpty())
+            Collection<?> collection = (Collection<?>) object;
+            if (collection.isEmpty())
+            {
+                return;
+            }
+            builder.append(name, CollectionUtils.abbreviate(collection, 100));
+        } else
         {
-            return;
+            builder.append(name, object);
         }
-        builder.append(name, CollectionUtils.abbreviate(collection, 100));
     }
 
 }
diff --git a/openbis/sourceTest/java/ch/systemsx/cisd/openbis/generic/shared/basic/dto/AtomicEntityOperationDetailsTest.java b/openbis/sourceTest/java/ch/systemsx/cisd/openbis/generic/shared/basic/dto/AtomicEntityOperationDetailsTest.java
index d0e17af17d29d6b5e03d2db87f813570b79f53af..4f2591a1281ad4fe7214081877273f674ac34493 100644
--- a/openbis/sourceTest/java/ch/systemsx/cisd/openbis/generic/shared/basic/dto/AtomicEntityOperationDetailsTest.java
+++ b/openbis/sourceTest/java/ch/systemsx/cisd/openbis/generic/shared/basic/dto/AtomicEntityOperationDetailsTest.java
@@ -107,7 +107,7 @@ public class AtomicEntityOperationDetailsTest extends AssertJUnit
         List<VocabularyUpdatesDTO> vocabularyUpdates = Collections.emptyList();
 
         AtomicEntityOperationDetails details =
-                new AtomicEntityOperationDetails(null, null, spaceRegistrations,
+                new AtomicEntityOperationDetails(new TechId(42), null, spaceRegistrations,
                         projectRegistrations, projectUpdates, experimentRegistrations,
                         experimentUpdates, sampleUpdates, sampleRegistrations,
                         materialRegistrations, materialUpdates,
@@ -119,7 +119,8 @@ public class AtomicEntityOperationDetailsTest extends AssertJUnit
 
         // Then
         assertEquals(
-                "AtomicEntityOperationDetails[spaceRegistrations=[S0, S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, "
+                "AtomicEntityOperationDetails[registrationIdOrNull=42,"
+                        + "spaceRegistrations=[S0, S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, "
                         + "S12, S13, S14, S15, S16, S17, S18, S19, S20, S21, S22, S23, S24, S25, S26, S27, S28, S29, "
                         + "S30, S31, S32, S33, S34, S35, S36, S37, S38, S39, S40, S41, S42, S43, S44, S45, S46, S47, "
                         + "S48, S49, S50, S51, S52, S53, S54, S55, S56, S57, S58, S59, S60, S61, S62, S63, S64, S65, "