diff --git a/deep_sequencing_unit/source/java/ch/ethz/bsse/cisd/dsu/tracking/main/TrackingBO.java b/deep_sequencing_unit/source/java/ch/ethz/bsse/cisd/dsu/tracking/main/TrackingBO.java
index 739c4a4ae792607413a9507d10967886bed250e9..e6d359e0c07d814529bee973cd091936dd989772 100644
--- a/deep_sequencing_unit/source/java/ch/ethz/bsse/cisd/dsu/tracking/main/TrackingBO.java
+++ b/deep_sequencing_unit/source/java/ch/ethz/bsse/cisd/dsu/tracking/main/TrackingBO.java
@@ -438,7 +438,9 @@ public class TrackingBO
             ArrayList<AbstractExternalData> toTransferDataSetsAll = new ArrayList<>(toTransferDataSetsHighPriority.size() + toTransferDataSets.size());
             toTransferDataSetsAll.addAll(toTransferDataSetsHighPriority);
             toTransferDataSetsAll.addAll(toTransferDataSets);
-            extraSCICOREDataSetListCopy(params, toTransferDataSetsAll);
+            if (!toTransferDataSetsAll.isEmpty()) {
+                extraSCICOREDataSetListCopy(params, toTransferDataSetsAll);
+            }
         }