diff --git a/Server/Python/src/dbs/business/DBSBlockInsert.py b/Server/Python/src/dbs/business/DBSBlockInsert.py
index e6980905..577632ed 100644
--- a/Server/Python/src/dbs/business/DBSBlockInsert.py
+++ b/Server/Python/src/dbs/business/DBSBlockInsert.py
@@ -254,8 +254,10 @@ def insertBlockFile(self, blockcontent, datasetId, migration=False):
                     hasFparentage = True
                     if migration:
                         fileParentList[k]['this_file_id'] = logicalFileName[fileParentList[k]['this_logical_file_name']]
-                        del fileParentList[k]['this_logical_file_name']
-                        del fileParentList[k]['parent_file_id']
+                        if 'this_logical_file_name' in fileParentList[k]:
+                            del fileParentList[k]['this_logical_file_name']
+                        if 'parent_file_id' in fileParentList[k]:
+                            del fileParentList[k]['parent_file_id']
                     else:
                         fileParentList[k]['this_file_id'] = logicalFileName[fileParentList[k]['logical_file_name']]
                         del fileParentList[k]['logical_file_name']