diff --git a/src/main/java/org/breedinginsight/brapps/importer/services/processors/experiment/ExperimentUtilities.java b/src/main/java/org/breedinginsight/brapps/importer/services/processors/experiment/ExperimentUtilities.java
index a215af40f..d37438b51 100644
--- a/src/main/java/org/breedinginsight/brapps/importer/services/processors/experiment/ExperimentUtilities.java
+++ b/src/main/java/org/breedinginsight/brapps/importer/services/processors/experiment/ExperimentUtilities.java
@@ -306,7 +306,7 @@ public static void addYearToStudyAdditionalInfo(Program program, BrAPIStudy stud
      * @throws IllegalStateException if any ObsUnit ID is repeated in the import rows
      * @throws HttpStatusException if there is a mix of ObsUnit IDs for some but not all rows
      */
-    public static Set<String> collateReferenceOUIds(AppendOverwriteMiddlewareContext context) {
+    public static Set<String> collateReferenceOUIds(AppendOverwriteMiddlewareContext context) throws HttpStatusException, IllegalStateException {
         // Initialize variables to track the presence of ObsUnit IDs
         Set<String> referenceOUIds = new HashSet<>();
         boolean hasNoReferenceUnitIds = true;
@@ -333,7 +333,7 @@ public static Set<String> collateReferenceOUIds(AppendOverwriteMiddlewareContext
 
         if (!hasNoReferenceUnitIds && !hasAllReferenceUnitIds) {
             // Throw exception if there is a mix of ObsUnit IDs for some but not all rows
-            throw new HttpStatusException(HttpStatus.UNPROCESSABLE_ENTITY, ExpImportProcessConstants.ErrMessage.MISSING_OBS_UNIT_ID_ERROR);
+            throw new HttpStatusException(HttpStatus.UNPROCESSABLE_ENTITY, ExpImportProcessConstants.ErrMessage.MISSING_OBS_UNIT_ID_ERROR.getValue());
         }
 
         return referenceOUIds;
diff --git a/src/main/java/org/breedinginsight/brapps/importer/services/processors/experiment/appendoverwrite/middleware/AppendOverwriteIDValidation.java b/src/main/java/org/breedinginsight/brapps/importer/services/processors/experiment/appendoverwrite/middleware/AppendOverwriteIDValidation.java
index 14bad6915..64f471b88 100644
--- a/src/main/java/org/breedinginsight/brapps/importer/services/processors/experiment/appendoverwrite/middleware/AppendOverwriteIDValidation.java
+++ b/src/main/java/org/breedinginsight/brapps/importer/services/processors/experiment/appendoverwrite/middleware/AppendOverwriteIDValidation.java
@@ -18,10 +18,12 @@
 package org.breedinginsight.brapps.importer.services.processors.experiment.appendoverwrite.middleware;
 
 import io.micronaut.context.annotation.Prototype;
+import io.micronaut.http.exceptions.HttpStatusException;
 import lombok.extern.slf4j.Slf4j;
 import org.breedinginsight.brapps.importer.services.processors.experiment.ExperimentUtilities;
 import org.breedinginsight.brapps.importer.services.processors.experiment.appendoverwrite.model.AppendOverwriteMiddlewareContext;
 import org.breedinginsight.brapps.importer.services.processors.experiment.appendoverwrite.model.AppendOverwriteMiddleware;
+import org.breedinginsight.brapps.importer.services.processors.experiment.appendoverwrite.model.MiddlewareException;
 
 @Slf4j
 @Prototype
@@ -29,18 +31,12 @@ public class AppendOverwriteIDValidation extends AppendOverwriteMiddleware {
     @Override
     public AppendOverwriteMiddlewareContext process(AppendOverwriteMiddlewareContext context) {
 
-        context.getAppendOverwriteWorkflowContext().setReferenceOUIds(ExperimentUtilities.collateReferenceOUIds(context));
+        try {
+            context.getAppendOverwriteWorkflowContext().setReferenceOUIds(ExperimentUtilities.collateReferenceOUIds(context));
+        } catch (HttpStatusException | IllegalStateException e) {
+            context.getAppendOverwriteWorkflowContext().setProcessError(new MiddlewareException(e));
+            return this.compensate(context);
+        }
         return processNext(context);
     }
-
-    @Override
-    public AppendOverwriteMiddlewareContext compensate(AppendOverwriteMiddlewareContext context) {
-        // tag an error if it occurred in this local transaction
-        context.getAppendOverwriteWorkflowContext().getProcessError().tag(this.getClass().getName());
-
-        // undo the prior local transaction
-        return compensatePrior(context);
-    }
-
-
 }
diff --git a/src/main/java/org/breedinginsight/brapps/importer/services/processors/experiment/model/ExpImportProcessConstants.java b/src/main/java/org/breedinginsight/brapps/importer/services/processors/experiment/model/ExpImportProcessConstants.java
index 72c0545b6..b4f7caf90 100644
--- a/src/main/java/org/breedinginsight/brapps/importer/services/processors/experiment/model/ExpImportProcessConstants.java
+++ b/src/main/java/org/breedinginsight/brapps/importer/services/processors/experiment/model/ExpImportProcessConstants.java
@@ -18,7 +18,7 @@ public class ExpImportProcessConstants {
 
     public enum ErrMessage {
         MULTIPLE_EXP_TITLES("File contains more than one Experiment Title"),
-        MISSING_OBS_UNIT_ID_ERROR("Experimental entities are missing ObsUnitIDs"),
+        MISSING_OBS_UNIT_ID_ERROR("Required field is blank"),
         PREEXISTING_EXPERIMENT_TITLE("Experiment Title already exists");
 
         private String value;