diff --git a/openbis/source/java/ch/systemsx/cisd/openbis/generic/client/web/client/application/ui/field/SampleChooserButton.java b/openbis/source/java/ch/systemsx/cisd/openbis/generic/client/web/client/application/ui/field/SampleChooserButton.java
index 7e6f4ba04404fe56eb18f95ada997c712fec6bfb..2e983c96efcc55070f35102344c5f9b295208685 100644
--- a/openbis/source/java/ch/systemsx/cisd/openbis/generic/client/web/client/application/ui/field/SampleChooserButton.java
+++ b/openbis/source/java/ch/systemsx/cisd/openbis/generic/client/web/client/application/ui/field/SampleChooserButton.java
@@ -152,6 +152,11 @@ public class SampleChooserButton extends Button implements
 
     public void setChosenEntities(List<TableModelRowWithObject<Sample>> entities)
     {
+        if (entities == null)
+        {
+            return;
+        }
+
         CommaSeparatedListBuilder builder = new CommaSeparatedListBuilder();
         for (TableModelRowWithObject<Sample> row : entities)
         {