diff --git a/akm_tools/validation/data_instance_validators.py b/akm_tools/validation/data_instance_validators.py
index d729738..cc3f8a6 100644
--- a/akm_tools/validation/data_instance_validators.py
+++ b/akm_tools/validation/data_instance_validators.py
@@ -83,8 +83,8 @@ def validate(self, instance: dict, **kwargs):
                             self.object_validators_dict[instance["entityTypeID"]].iter_errors(instance),
                             key=lambda e: e.path,
                         )
-                    base_error_msg += "\n".join(x.message for x in additioanl_error_info)
-                    base_error_msg += "\n"
+                        base_error_msg += "\n".join(x.message for x in additioanl_error_info)
+                        base_error_msg += "\n"
                 return False, base_error_msg
         except Exception as e:
             raise e
diff --git a/tests/conftest.py b/tests/conftest.py
index c71549e..2dfdf9b 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -12,8 +12,9 @@ def simple_schema():
             "type": {"type": "string"},
             "age": {"type": "number"},
             "id": {"type": "string"},
+            "entityTypeID": {"type": "string"},
         },
-        "required": ["id"],
+        "required": ["id", "entityTypeID"],
         "additionalProperties": False,
     }
     return schema
@@ -22,8 +23,8 @@ def simple_schema():
 @pytest.fixture
 def simple_data():
     data = [
-        {"type": "John", "age": 30, "id": "unique_id_1"},
-        {"type": "Jane", "age": 25, "id": "unique_id_2"},
+        {"type": "John", "age": 30, "id": "unique_id_1", "entityTypeID": "type1"},
+        {"type": "Jane", "age": 25, "id": "unique_id_2", "entityTypeID": "type2"},
     ]
     return data
 
@@ -31,15 +32,18 @@ def simple_data():
 @pytest.fixture
 def simple_data_with_more_attributes():
     data = [
-        {"type": "John", "age": 30, "id": "unique_id_1", "extra_attribute": "wild"},
-        {"type": "Jane", "age": 25, "id": "unique_id_2", "extra_attribute": "grass"},
+        {"type": "John", "age": 30, "id": "unique_id_1", "entityTypeID": "type1", "extra_attribute": "wild"},
+        {"type": "Jane", "age": 25, "id": "unique_id_2", "entityTypeID": "type2", "extra_attribute": "grass"},
     ]
     return data
 
 
 @pytest.fixture
 def simple_data_without_required_attribute():
-    data = [{"type": "John", "age": 30}, {"type": "Jane", "age": 25}]
+    data = [
+        {"type": "John", "age": 30, "entityTypeID": "type1"},
+        {"type": "Jane", "age": 25, "entityTypeID": "type2"}
+    ]
     return data
 
 
@@ -58,9 +62,10 @@ def complex_schema_with_defs():
                 "type": "object",
                 "properties": {
                     "id": {"type": "string"},
+                    "entityTypeID": {"type": "string"},
                     "definition": {"type": "string"},
                 },
-                "required": ["id"],
+                "required": ["id", "entityTypeID"],
             },
             "ObjectType1": {
                 "$id": "complexSchema.ObjectType1",
@@ -69,7 +74,6 @@ def complex_schema_with_defs():
                 "properties": {
                     "name": {"type": "string"},
                     "description": {"type": "string"},
-                    "type": {"type": "string", "const": "ObjectType1"},
                 },
                 "required": ["name", "type"],
                 "unevaluatedProperties": False,
@@ -80,7 +84,6 @@ def complex_schema_with_defs():
                 "allOf": [{"$ref": "complexSchema.BaseClass"}],
                 "properties": {
                     "age": {"type": "number"},
-                    "type": {"type": "string", "const": "ObjectType2"},
                 },
                 "required": ["type"],
                 "unevaluatedProperties": False,
@@ -97,27 +100,25 @@ def complex_data():
     data = [
         {
             "id": "unique_id_1",
+            "entityTypeID": "type1",
             "definition": "Some def1",
             "name": "AttributeName",
-            "type": "ObjectType1",
             "description": "some desc",
         },
-        {"id": "unique_id_2", "type": "ObjectType2", "age": 10},
+        {"id": "unique_id_2", "entityTypeID": "type2",  "age": 10},
     ]
     return data
 
 
 @pytest.fixture
-def complex_data_missing_required_attributes():  ## id/type is missing.
+def complex_data_missing_required_attributes():  ## id/entityTypeID is missing.
     data = [
         {
             "definition": "Some def1",
             "name": "AttributeName",
-            "type": "ObjectType1",
             "description": "some desc",
         },
         {
-            "type": "ObjectType2",
             "age": 10,
         },
     ]
@@ -129,15 +130,15 @@ def complex_data_with_additional_attributes():
     data = [
         {
             "id": "unique_id_1",
+            "entityTypeID": "typObjectType1e1",
             "definition": "Some def1",
             "name": "AttributeName",
-            "type": "ObjectType1",
             "description": "some desc",
             "extra_attribute": "wild",
         },
         {
             "id": "unique_id_2",
-            "type": "ObjectType2",
+            "entityTypeID": "ObjectType2",
             "age": 10,
             "extra_attribute": "grass",
         },
@@ -150,16 +151,16 @@ def data_with_duplicate_ids():
     data = [
         {
             "id": "unique_id_1",
+            "entityTypeID": "type1",
             "definition": "Some def1",
             "name": "AttributeName",
-            "type": "ObjectType1",
             "description": "some desc",
         },
         {
             "id": "unique_id_1",
+            "entityTypeID": "type1",
             "definition": "Some def2",
             "name": "AttributeName2",
-            "type": "ObjectType2",
             "description": "some desc2",
         },
     ]
@@ -167,7 +168,7 @@ def data_with_duplicate_ids():
 
 
 @pytest.fixture
-def scehma_with_extensions():
+def schema_with_extensions():
     schema = {
         "$schema": "https://json-schema.org/draft/2020-12/schema",
         "$id": "schema_with_extensions",
@@ -180,7 +181,7 @@ def scehma_with_extensions():
             "description": {"type": "string"},
             "entityType": {"type": "string", "const": "ObjectType3"},
         },
-        "required": ["entityType"],
+        "required": ["id","entityType"],
         "unevaluatedProperties": False,
     }
     schema_extension = {
@@ -225,7 +226,7 @@ def overlay_existing_data_with_addional_properties():
 
 
 @pytest.fixture
-def ovewrite_existing_data():
+def overwrite_existing_data():
     data = [
         {
             "id": "unique_id1",
diff --git a/tests/test_CoreJsonSchemaValidator.py b/tests/test_CoreJsonSchemaValidator.py
index a84d678..3d243e1 100644
--- a/tests/test_CoreJsonSchemaValidator.py
+++ b/tests/test_CoreJsonSchemaValidator.py
@@ -68,8 +68,8 @@ def test_complex_data_validator_with_invalid_attribute(complex_schema_with_defs,
     assert all(valid_data) == False
 
 
-def test_complex_data_validator_with_extended_data(scehma_with_extensions, data_with_extended_properties):
-    schema, registry = scehma_with_extensions
+def test_complex_data_validator_with_extended_data(schema_with_extensions, data_with_extended_properties):
+    schema, registry = schema_with_extensions
     complex_data_validator = CoreJsonSchemaValidator(schema=schema, extended_schema_dir=None)
     complex_data_validator.configure_registry(registry)
     valid_data = []
@@ -79,8 +79,8 @@ def test_complex_data_validator_with_extended_data(scehma_with_extensions, data_
     assert all(valid_data) == True
 
 
-def test_complex_data_validator_with_extended_data(scehma_with_extensions, overlay_existing_data_with_addional_properties):
-    schema, registry = scehma_with_extensions
+def test_complex_data_validator_with_overlaid_data(schema_with_extensions, overlay_existing_data_with_addional_properties):
+    schema, registry = schema_with_extensions
     complex_data_validator = CoreJsonSchemaValidator(schema=schema, extended_schema_dir=None)
     complex_data_validator.configure_registry(registry)
     valid_data = []
@@ -88,3 +88,14 @@ def test_complex_data_validator_with_extended_data(scehma_with_extensions, overl
         is_valid, _ = complex_data_validator.validate(instance=instance)
         valid_data.append(is_valid)
     assert all(valid_data) == True
+
+
+def test_complex_data_validator_with_overwritten_data(schema_with_extensions, overwrite_existing_data):
+    schema, registry = schema_with_extensions
+    complex_data_validator = CoreJsonSchemaValidator(schema=schema, extended_schema_dir=None)
+    complex_data_validator.configure_registry(registry)
+    valid_data = []
+    for instance in overwrite_existing_data:
+        is_valid, _ = complex_data_validator.validate(instance=instance)
+        valid_data.append(is_valid)
+    assert all(valid_data) == False