diff --git a/api_app/api/routes/resource_helpers.py b/api_app/api/routes/resource_helpers.py
index d3dff6594f..c949a968fa 100644
--- a/api_app/api/routes/resource_helpers.py
+++ b/api_app/api/routes/resource_helpers.py
@@ -26,6 +26,8 @@
 )
 from services.authentication import get_access_service
 from services.logging import logger
+from services.access_service import AuthConfigValidationError
+from core import config
 
 
 async def delete_validation(resource: Resource, resource_repo: ResourceRepository):
@@ -158,7 +160,12 @@ def construct_location_header(operation: Operation) -> str:
 
 def get_identity_role_assignments(user):
     access_service = get_access_service()
-    return access_service.get_identity_role_assignments(user.id)
+    try:
+        return access_service.get_identity_role_assignments(user.id)
+    except AuthConfigValidationError:
+        if config.USER_MANAGEMENT_ENABLED:
+            raise
+        return []
 
 
 def get_app_user_roles_assignments_emails(app_obj_id):
diff --git a/api_app/tests_ma/conftest.py b/api_app/tests_ma/conftest.py
index 6245ec23ec..bc6155ada7 100644
--- a/api_app/tests_ma/conftest.py
+++ b/api_app/tests_ma/conftest.py
@@ -1,6 +1,6 @@
 import pytest
 import pytest_asyncio
-from mock import AsyncMock, patch
+from unittest.mock import AsyncMock, patch
 from azure.cosmos.aio import CosmosClient, DatabaseProxy
 
 from api.dependencies.database import Database
diff --git a/api_app/tests_ma/test_api/conftest.py b/api_app/tests_ma/test_api/conftest.py
index b386ce32bd..99be35034d 100644
--- a/api_app/tests_ma/test_api/conftest.py
+++ b/api_app/tests_ma/test_api/conftest.py
@@ -1,6 +1,6 @@
 import pytest
 import pytest_asyncio
-from mock import patch
+from unittest.mock import patch
 
 from fastapi import FastAPI
 from httpx import AsyncClient
diff --git a/api_app/tests_ma/test_api/test_routes/test_resource_helpers.py b/api_app/tests_ma/test_api/test_routes/test_resource_helpers.py
index 31fb31e5f1..9d1f4bf0cb 100644
--- a/api_app/tests_ma/test_api/test_routes/test_resource_helpers.py
+++ b/api_app/tests_ma/test_api/test_routes/test_resource_helpers.py
@@ -1,9 +1,59 @@
+from types import SimpleNamespace
+import pytest
+from unittest.mock import patch
+
+from services.access_service import AuthConfigValidationError
+
+
+@patch("api.routes.resource_helpers.get_access_service")
+def test_get_identity_role_assignments_fallback_when_user_mgmt_disabled(get_access_service_mock, monkeypatch):
+    # Arrange: access service raises auth config error
+    class FakeAccessService:
+        def get_identity_role_assignments(self, user_id: str):
+            raise AuthConfigValidationError("graph not available")
+
+    get_access_service_mock.return_value = FakeAccessService()
+
+    # Force feature disabled using monkeypatch to avoid test pollution
+    from core import config as core_config
+    monkeypatch.setattr(core_config, "USER_MANAGEMENT_ENABLED", False)
+
+    from api.routes import resource_helpers
+    user = SimpleNamespace(id="user-id")
+
+    # Act
+    result = resource_helpers.get_identity_role_assignments(user)
+
+    # Assert
+    assert result == []
+
+
+@patch("api.routes.resource_helpers.get_access_service")
+def test_get_identity_role_assignments_raises_when_user_mgmt_enabled(get_access_service_mock, monkeypatch):
+    # Arrange: access service raises auth config error
+    class FakeAccessService:
+        def get_identity_role_assignments(self, user_id: str):
+            raise AuthConfigValidationError("graph not available")
+
+    get_access_service_mock.return_value = FakeAccessService()
+
+    # Force feature enabled using monkeypatch to avoid test pollution
+    from core import config as core_config
+    monkeypatch.setattr(core_config, "USER_MANAGEMENT_ENABLED", True)
+
+    from api.routes import resource_helpers
+    user = SimpleNamespace(id="user-id")
+
+    # Act / Assert
+    with pytest.raises(AuthConfigValidationError):
+        resource_helpers.get_identity_role_assignments(user)
+
 import datetime
 from unittest.mock import AsyncMock
 import uuid
 import pytest
 import pytest_asyncio
-from mock import patch
+from unittest.mock import patch
 import json
 
 from fastapi import HTTPException, status