diff --git a/api/services/plugin/plugin_migration.py b/api/services/plugin/plugin_migration.py
index d6f154df812..5c2ddb77e0f 100644
--- a/api/services/plugin/plugin_migration.py
+++ b/api/services/plugin/plugin_migration.py
@@ -416,10 +416,9 @@ class PluginMigration:
                 data = _tenant_plugin_adapter.validate_json(line)
                 tenant_id = data["tenant_id"]
                 plugin_ids = data["plugins"]
-                plugin_not_exist: list[str] = []
-                for plugin_id in plugin_ids:
-                    if plugin_id not in package_identifier_by_plugin_id:
-                        plugin_not_exist.append(plugin_id)
+                plugin_not_exist = [
+                    plugin_id for plugin_id in plugin_ids if plugin_id not in package_identifier_by_plugin_id
+                ]
 
                 if plugin_not_exist:
                     not_installed.append(
diff --git a/api/tests/unit_tests/services/plugin/test_plugin_migration.py b/api/tests/unit_tests/services/plugin/test_plugin_migration.py
index fa10d775aa6..d94ab540dfd 100644
--- a/api/tests/unit_tests/services/plugin/test_plugin_migration.py
+++ b/api/tests/unit_tests/services/plugin/test_plugin_migration.py
@@ -148,5 +148,35 @@ class TestHandlePluginInstanceInstall:
             PluginMigration.install_plugins(str(extracted_plugins), str(output_file), workers=1)
 
         assert json.loads(output_file.read_text())["not_installed"] == [
-            {"tenant_id": "tenant1", "plugin_not_exist": ["langgenius/missing"]}
+            {
+                "tenant_id": "tenant1",
+                "plugin_not_exist": ["langgenius/missing"],
+            }
         ]
+        mock_installer.install_from_identifiers.assert_called_once()
+
+    def test_install_plugins_skips_unresolved_plugins(self, tmp_path) -> None:
+        extracted_plugins = tmp_path / "plugins.jsonl"
+        output_file = tmp_path / "output.json"
+        extracted_plugins.write_text('{"tenant_id":"tenant1","plugins":["langgenius/missing"]}\n')
+
+        with (
+            patch(
+                f"{MIGRATION_MODULE}.PluginMigration.extract_unique_plugins",
+                return_value={
+                    "plugins": {},
+                    "plugin_not_exist": ["langgenius/missing"],
+                },
+            ),
+            patch(f"{MIGRATION_MODULE}.PluginMigration.handle_plugin_instance_install", return_value={}),
+            patch(f"{MIGRATION_MODULE}.PluginInstaller") as mock_installer_cls,
+        ):
+            mock_installer = MagicMock()
+            mock_installer.list_plugins.return_value = []
+            mock_installer_cls.return_value = mock_installer
+
+            PluginMigration.install_plugins(str(extracted_plugins), str(output_file), workers=1)
+
+        output = json.loads(output_file.read_text())
+        assert output["not_installed"] == [{"tenant_id": "tenant1", "plugin_not_exist": ["langgenius/missing"]}]
+        mock_installer.install_from_identifiers.assert_not_called()
diff --git a/api/tests/unit_tests/services/rag_pipeline/test_rag_pipeline_dsl_service.py b/api/tests/unit_tests/services/rag_pipeline/test_rag_pipeline_dsl_service.py
index 93884d07c5c..5cdb2afd093 100644
--- a/api/tests/unit_tests/services/rag_pipeline/test_rag_pipeline_dsl_service.py
+++ b/api/tests/unit_tests/services/rag_pipeline/test_rag_pipeline_dsl_service.py
@@ -633,6 +633,19 @@ def test_import_rag_pipeline_yaml_content_requires_content() -> None:
     assert "yaml_content is required" in result.error
 
 
+def test_import_rag_pipeline_rejects_oversized_yaml_content_before_parsing(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setattr("services.rag_pipeline.rag_pipeline_dsl_service.DSL_MAX_SIZE", 3)
+    service = RagPipelineDslService(session=Mock())
+    account = Mock(current_tenant_id="t1")
+
+    result = service.import_rag_pipeline(account=account, import_mode="yaml-content", yaml_content="你你")
+
+    assert result.status == ImportStatus.FAILED
+    assert result.error == "File size exceeds the limit of 10MB"
+
+
 def test_import_rag_pipeline_yaml_content_requires_mapping() -> None:
     service = RagPipelineDslService(session=Mock())
     account = Mock(current_tenant_id="t1")
diff --git a/api/tests/unit_tests/services/test_app_dsl_service.py b/api/tests/unit_tests/services/test_app_dsl_service.py
index 64236ea5a90..ae621bdcf52 100644
--- a/api/tests/unit_tests/services/test_app_dsl_service.py
+++ b/api/tests/unit_tests/services/test_app_dsl_service.py
@@ -1,50 +1,49 @@
-from types import SimpleNamespace
 from unittest.mock import Mock
 
-from services.app_dsl_service import AppDslService, ImportStatus
+import pytest
+
+from services.app_dsl_service import AppDslService
+from services.entities.dsl_entities import ImportStatus
 
 
-def test_import_app_rejects_oversized_yaml_content_by_bytes(monkeypatch) -> None:
-    monkeypatch.setattr("services.app_dsl_service.DSL_MAX_SIZE", 1)
-    service = AppDslService(session=SimpleNamespace())
+def test_import_app_rejects_oversized_yaml_content_before_parsing(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setattr("services.app_dsl_service.DSL_MAX_SIZE", 3)
+    service = AppDslService(session=Mock())
+    account = Mock(current_tenant_id="tenant-1")
 
-    result = service.import_app(
-        account=SimpleNamespace(current_tenant_id="tenant-1"),
-        import_mode="yaml-content",
-        yaml_content="é",
-    )
+    result = service.import_app(account=account, import_mode="yaml-content", yaml_content="你你")
 
     assert result.status == ImportStatus.FAILED
-    assert "10MB" in result.error
+    assert result.error == "File size exceeds the limit of 10MB"
 
 
-def test_import_app_rejects_oversized_yaml_url_bytes_before_decode(monkeypatch) -> None:
+def test_import_app_rejects_oversized_yaml_url_bytes_before_decode(monkeypatch: pytest.MonkeyPatch) -> None:
     monkeypatch.setattr("services.app_dsl_service.DSL_MAX_SIZE", 1)
     response = Mock()
     response.raise_for_status.return_value = None
     response.content = b"\xff\xff"
     monkeypatch.setattr("services.app_dsl_service.remote_fetcher.make_request", Mock(return_value=response))
-    service = AppDslService(session=SimpleNamespace())
+    service = AppDslService(session=Mock())
 
     result = service.import_app(
-        account=SimpleNamespace(current_tenant_id="tenant-1"),
+        account=Mock(current_tenant_id="tenant-1"),
         import_mode="yaml-url",
         yaml_url="https://example.com/app.yaml",
     )
 
     assert result.status == ImportStatus.FAILED
-    assert "10MB" in result.error
+    assert result.error == "File size exceeds the limit of 10MB"
 
 
-def test_import_app_returns_decode_error_for_invalid_yaml_url_bytes(monkeypatch) -> None:
+def test_import_app_returns_decode_error_for_invalid_yaml_url_bytes(monkeypatch: pytest.MonkeyPatch) -> None:
     response = Mock()
     response.raise_for_status.return_value = None
     response.content = b"\xff"
     monkeypatch.setattr("services.app_dsl_service.remote_fetcher.make_request", Mock(return_value=response))
-    service = AppDslService(session=SimpleNamespace())
+    service = AppDslService(session=Mock())
 
     result = service.import_app(
-        account=SimpleNamespace(current_tenant_id="tenant-1"),
+        account=Mock(current_tenant_id="tenant-1"),
         import_mode="yaml-url",
         yaml_url="https://example.com/app.yaml",
     )