diff --git a/src/main/java/edu/tamu/scholars/discovery/etl/model/repo/handler/DataHandler.java b/src/main/java/edu/tamu/scholars/discovery/etl/model/repo/handler/DataHandler.java
index b0ccff2f0..0cc420fb7 100644
--- a/src/main/java/edu/tamu/scholars/discovery/etl/model/repo/handler/DataHandler.java
+++ b/src/main/java/edu/tamu/scholars/discovery/etl/model/repo/handler/DataHandler.java
@@ -22,6 +22,7 @@ public void validateBeforeSave(Data data) {
     public void validateRequiredAttribute(Data data) {
         // validate data before create or save
         // validate extractor, transformer, and loader are all compatible
+        // validate fields descriptor name/reference key do not have conflicting fields
     }
 
 }
diff --git a/src/main/java/edu/tamu/scholars/discovery/etl/transform/FlatMapToSolrInputDocumentTransformer.java b/src/main/java/edu/tamu/scholars/discovery/etl/transform/FlatMapToSolrInputDocumentTransformer.java
index c83a1c9b8..8be195bd3 100644
--- a/src/main/java/edu/tamu/scholars/discovery/etl/transform/FlatMapToSolrInputDocumentTransformer.java
+++ b/src/main/java/edu/tamu/scholars/discovery/etl/transform/FlatMapToSolrInputDocumentTransformer.java
@@ -203,6 +203,10 @@ private void processSimpleStructure(DataFieldDescriptor nestedDescriptor, SolrIn
     private void processSingleValuedNestedReference(Map<String, Object> data, String parentId, DataFieldDescriptor nestedDescriptor, SolrInputDocument childDocument, int depth) {
         Object nestedObject = data.remove(nestedDescriptor.getName());
 
+        if (nestedObject == null) {
+            return;
+        }
+
         String[] nestedParts = NESTED_DELIMITER_PATTERN.split(nestedObject.toString());
 
         if (nestedParts.length > depth) {