diff --git a/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/yaml/reconcile/ApplicationYamlASTReconciler.java b/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/yaml/reconcile/ApplicationYamlASTReconciler.java
index 780cfc584..8b7c48250 100644
--- a/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/yaml/reconcile/ApplicationYamlASTReconciler.java
+++ b/headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/yaml/reconcile/ApplicationYamlASTReconciler.java
@@ -155,6 +155,10 @@ public class ApplicationYamlASTReconciler implements YamlASTReconciler {
 				IndexNavigator subNavAlias = nav.selectSubProperty(key);
 				match = subNavAlias.getExactMatch();
 				extension = subNavAlias.getExtensionCandidate();
+				if (subNav==null) {
+					//ensure subnav is not null, even if no real matches found.
+					subNav = subNavAlias;
+				}
 				if (match!=null || extension!=null) {
 					subNav = subNavAlias;
 					break; //stop at first alias that gives a result.
diff --git a/headless-services/spring-boot-language-server/src/test/java/org/springframework/ide/vscode/boot/test/ApplicationYamlEditorTest.java b/headless-services/spring-boot-language-server/src/test/java/org/springframework/ide/vscode/boot/test/ApplicationYamlEditorTest.java
index 4a2b6550a..dbed58789 100644
--- a/headless-services/spring-boot-language-server/src/test/java/org/springframework/ide/vscode/boot/test/ApplicationYamlEditorTest.java
+++ b/headless-services/spring-boot-language-server/src/test/java/org/springframework/ide/vscode/boot/test/ApplicationYamlEditorTest.java
@@ -78,20 +78,6 @@ public class ApplicationYamlEditorTest extends AbstractPropsEditorTest {
 		
 		Editor editor;
 
-		//Also check whether reconciler understands the structure when inside of a 'relaxed' name key 
-		editor = harness.newEditor(
-				"spring:\n" + 
-				"  resources:\n" + 
-				"    static_locations: bad\n" + 
-				"  devtools:\n" + 
-				"    restart:\n" + 
-				"      additional_paths: wrong\n"
-		);
-		editor.assertProblems(
-				"bad|boolean", //TODO: fill in proper expected message instead of XXXX
-				"wrong|boolean"  //TODO: fill in proper expected message instead of XXXX
-		);
-
 		// basic check
 		editor = harness.newEditor(
 				"spring:\n" + 
@@ -102,6 +88,20 @@ public class ApplicationYamlEditorTest extends AbstractPropsEditorTest {
 				"      additional_paths: false\n"
 		);
 		editor.assertProblems(/*NONE*/);
+
+		//Also check whether reconciler understands the structure when inside of a 'relaxed' name key 
+		editor = harness.newEditor(
+				"spring:\n" + 
+				"  resources:\n" + 
+				"    static_locations: bad\n" + 
+				"  devtools:\n" + 
+				"    restart:\n" + 
+				"      additional_paths: wrong\n"
+		);
+		editor.assertProblems(
+				"bad|boolean",
+				"wrong|boolean"
+		);
 	}
 	
 	@Test public void bug_165724475() throws Exception {