diff --git a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/ChannelChooserPanel.java b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/ChannelChooserPanel.java
index 02aae0b84ecc5799c3e0b6c365bffefd55b03067..0012c3edaeb5f507127c4cafe6e73badc7b6a10c 100644
--- a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/ChannelChooserPanel.java
+++ b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/ChannelChooserPanel.java
@@ -430,7 +430,14 @@ public class ChannelChooserPanel extends LayoutContainer
 
     public IntensityRange tryGetSelectedIntensityRange()
     {
-        return intensitiesPerChannel.get(getSelectedValues().get(0));
+        List<String> selectedValues = getSelectedValues();
+        if (selectedValues != null && selectedValues.size() > 0)
+        {
+            return intensitiesPerChannel.get(getSelectedValues().get(0));
+        } else
+        {
+            return null;
+        }
     }
 
     private static String transformCode(String code)