diff --git a/plugins/tiles/src/main/java/org/apache/struts2/tiles/StrutsTilesContainerFactory.java b/plugins/tiles/src/main/java/org/apache/struts2/tiles/StrutsTilesContainerFactory.java
index f1c8bbb11..b7564a943 100644
--- a/plugins/tiles/src/main/java/org/apache/struts2/tiles/StrutsTilesContainerFactory.java
+++ b/plugins/tiles/src/main/java/org/apache/struts2/tiles/StrutsTilesContainerFactory.java
@@ -190,9 +190,13 @@ public class StrutsTilesContainerFactory extends BasicTilesContainerFactory {
             resources.addAll(applicationContext.getResources(definition));
         }
 
+        if (resources.contains(null)) {
+            LOG.warn("Some resources were not found. Definitions: {}. Found resources: {}", definitions, resources);
+        }
+
         List<ApplicationResource> filteredResources = new ArrayList<>();
         for (ApplicationResource resource : resources) {
-            if (Locale.ROOT.equals(resource.getLocale())) {
+            if (resource != null && Locale.ROOT.equals(resource.getLocale())) {
                 filteredResources.add(resource);
             }
         }