diff --git a/plugin/src/main/java/org/opensearch/ml/action/model_group/TransportUpdateModelGroupAction.java b/plugin/src/main/java/org/opensearch/ml/action/model_group/TransportUpdateModelGroupAction.java
index 494f197857..9d6dc32b86 100644
--- a/plugin/src/main/java/org/opensearch/ml/action/model_group/TransportUpdateModelGroupAction.java
+++ b/plugin/src/main/java/org/opensearch/ml/action/model_group/TransportUpdateModelGroupAction.java
@@ -9,7 +9,6 @@
 import static org.opensearch.ml.common.CommonValue.ML_MODEL_GROUP_INDEX;
 import static org.opensearch.ml.utils.MLExceptionUtils.logException;
 
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;
@@ -90,39 +89,41 @@ protected void doExecute(Task task, ActionRequest request, ActionListener<MLUpda
         MLUpdateModelGroupInput updateModelGroupInput = updateModelGroupRequest.getUpdateModelGroupInput();
         String modelGroupId = updateModelGroupInput.getModelGroupID();
         User user = RestActionUtils.getUserContext(client);
-        if (modelAccessControlHelper.isSecurityEnabledAndModelAccessControlEnabled(user)) {
-            GetRequest getModelGroupRequest = new GetRequest(ML_MODEL_GROUP_INDEX).id(modelGroupId);
-            try (ThreadContext.StoredContext context = client.threadPool().getThreadContext().stashContext()) {
-                ActionListener<MLUpdateModelGroupResponse> wrappedListener = ActionListener.runBefore(listener, () -> context.restore());
-                client.get(getModelGroupRequest, ActionListener.wrap(modelGroup -> {
-                    if (modelGroup.isExists()) {
-                        try (
-                            XContentParser parser = MLNodeUtils
-                                .createXContentParserFromRegistry(NamedXContentRegistry.EMPTY, modelGroup.getSourceAsBytesRef())
-                        ) {
-                            ensureExpectedToken(XContentParser.Token.START_OBJECT, parser.nextToken(), parser);
-                            MLModelGroup mlModelGroup = MLModelGroup.parse(parser);
+        GetRequest getModelGroupRequest = new GetRequest(ML_MODEL_GROUP_INDEX).id(modelGroupId);
+        try (ThreadContext.StoredContext context = client.threadPool().getThreadContext().stashContext()) {
+            ActionListener<MLUpdateModelGroupResponse> wrappedListener = ActionListener.runBefore(listener, () -> context.restore());
+            client.get(getModelGroupRequest, ActionListener.wrap(modelGroup -> {
+                if (modelGroup.isExists()) {
+                    try (
+                        XContentParser parser = MLNodeUtils
+                            .createXContentParserFromRegistry(NamedXContentRegistry.EMPTY, modelGroup.getSourceAsBytesRef())
+                    ) {
+                        ensureExpectedToken(XContentParser.Token.START_OBJECT, parser.nextToken(), parser);
+                        MLModelGroup mlModelGroup = MLModelGroup.parse(parser);
+                        if (modelAccessControlHelper.isSecurityEnabledAndModelAccessControlEnabled(user)) {
                             validateRequestForAccessControl(updateModelGroupInput, user, mlModelGroup);
-                            updateModelGroup(modelGroupId, modelGroup.getSource(), updateModelGroupInput, wrappedListener, user);
+                        } else {
+                            validateSecurityDisabledOrModelAccessControlDisabled(updateModelGroupInput);
                         }
-                    } else {
-                        wrappedListener.onFailure(new OpenSearchStatusException("Failed to find model group", RestStatus.NOT_FOUND));
-                    }
-                }, e -> {
-                    if (e instanceof IndexNotFoundException) {
-                        wrappedListener.onFailure(new MLResourceNotFoundException("Fail to find model group"));
-                    } else {
-                        logException("Failed to get model group", e, log);
+                        updateModelGroup(modelGroupId, modelGroup.getSource(), updateModelGroupInput, wrappedListener, user);
+                    } catch (Exception e) {
+                        log.error("Failed to parse ml model group" + modelGroup.getId(), e);
                         wrappedListener.onFailure(e);
                     }
-                }));
-            } catch (Exception e) {
-                logException("Failed to Update model group", e, log);
-                listener.onFailure(e);
-            }
-        } else {
-            validateSecurityDisabledOrModelAccessControlDisabled(updateModelGroupInput);
-            updateModelGroup(modelGroupId, new HashMap<>(), updateModelGroupInput, listener, user);
+                } else {
+                    wrappedListener.onFailure(new OpenSearchStatusException("Failed to find model group", RestStatus.NOT_FOUND));
+                }
+            }, e -> {
+                if (e instanceof IndexNotFoundException) {
+                    wrappedListener.onFailure(new MLResourceNotFoundException("Fail to find model group"));
+                } else {
+                    logException("Failed to get model group", e, log);
+                    wrappedListener.onFailure(e);
+                }
+            }));
+        } catch (Exception e) {
+            logException("Failed to Update model group", e, log);
+            listener.onFailure(e);
         }
     }
 
diff --git a/plugin/src/test/java/org/opensearch/ml/action/model_group/TransportUpdateModelGroupActionTests.java b/plugin/src/test/java/org/opensearch/ml/action/model_group/TransportUpdateModelGroupActionTests.java
index 1a67977291..a99488d0e9 100644
--- a/plugin/src/test/java/org/opensearch/ml/action/model_group/TransportUpdateModelGroupActionTests.java
+++ b/plugin/src/test/java/org/opensearch/ml/action/model_group/TransportUpdateModelGroupActionTests.java
@@ -38,6 +38,7 @@
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
+import org.opensearch.index.IndexNotFoundException;
 import org.opensearch.index.get.GetResult;
 import org.opensearch.ml.common.AccessMode;
 import org.opensearch.ml.common.MLModelGroup;
@@ -367,6 +368,20 @@ public void test_FailedToGetModelGroupException() {
         assertEquals("Failed to get model group", argumentCaptor.getValue().getMessage());
     }
 
+    public void test_ModelGroupIndexNotFoundException() {
+        doAnswer(invocation -> {
+            ActionListener<GetResponse> actionListener = invocation.getArgument(1);
+            actionListener.onFailure(new IndexNotFoundException("Fail to find model group"));
+            return null;
+        }).when(client).get(any(), any());
+
+        MLUpdateModelGroupRequest actionRequest = prepareRequest(null, AccessMode.RESTRICTED, null);
+        transportUpdateModelGroupAction.doExecute(task, actionRequest, actionListener);
+        ArgumentCaptor<Exception> argumentCaptor = ArgumentCaptor.forClass(Exception.class);
+        verify(actionListener).onFailure(argumentCaptor.capture());
+        assertEquals("Fail to find model group", argumentCaptor.getValue().getMessage());
+    }
+
     public void test_FailedToUpdatetModelGroupException() {
         doAnswer(invocation -> {
             ActionListener<UpdateResponse> listener = invocation.getArgument(1);
@@ -414,15 +429,16 @@ public void test_ModelGroupNameNotUnique() throws IOException {
     }
 
     public void test_ExceptionSecurityDisabledCluster() {
-        exceptionRule.expect(IllegalArgumentException.class);
-        exceptionRule
-            .expectMessage(
-                "You cannot specify model access control parameters because the Security plugin or model access control is disabled on your cluster."
-            );
         when(modelAccessControlHelper.isSecurityEnabledAndModelAccessControlEnabled(any())).thenReturn(false);
 
         MLUpdateModelGroupRequest actionRequest = prepareRequest(null, null, true);
         transportUpdateModelGroupAction.doExecute(task, actionRequest, actionListener);
+        ArgumentCaptor<Exception> argumentCaptor = ArgumentCaptor.forClass(Exception.class);
+        verify(actionListener).onFailure(argumentCaptor.capture());
+        assertEquals(
+                "You cannot specify model access control parameters because the Security plugin or model access control is disabled on your cluster.",
+                argumentCaptor.getValue().getMessage()
+        );
     }
 
     private MLUpdateModelGroupRequest prepareRequest(List<String> backendRoles, AccessMode modelAccessMode, Boolean isAddAllBackendRoles) {