Try tf 2.18.0 version.

.github/actions/keras_application_test/action.yml

@@ -58,6 +58,7 @@ runs:
               pip install numpy==1.19.0
           else 
               pip install transformers
+              pip install tf_keras
               pip install "numpy<2"
           fi
 
@@ -71,5 +72,7 @@ runs:
       run: |
           python -c "import onnxruntime"
           pytest tests/keras2onnx_unit_tests --doctest-modules --junitxml=junit/test-results.xml
+
+          export TF_USE_LEGACY_KERAS=True
           cd tests/keras2onnx_applications/nightly_build
           python run_all_v2.py

.github/actions/keras_unit_test/action.yml

@@ -36,6 +36,7 @@ runs:
           if [[ ${{ inputs.tf_version }} == 1.* ]]; then 
               pip install numpy==1.19.0
           else 
+              pip install tf_keras
               pip install "numpy<2"
           fi
 
@@ -48,6 +49,7 @@ runs:
       shell: bash
       if: runner.os == 'Linux'
       run: |
+          export TF_USE_LEGACY_KERAS=True
           python -c "import onnxruntime"
           python -c "import onnxconverter_common"
           pytest tests/keras2onnx_unit_tests --doctest-modules --junitxml=junit/test-results.xml

.github/actions/unit_test/action.yml

@@ -46,6 +46,7 @@ runs:
         export TF2ONNX_SKIP_TFLITE_TESTS=${{ inputs.skip_tflite }}
         export TF2ONNX_SKIP_TFJS_TESTS=True
         export TF2ONNX_SKIP_TF_TESTS=False
+        export TF_USE_LEGACY_KERAS=True
         python -m pytest --cov=tf2onnx --cov-report=term --disable-pytest-warnings -r s tests --cov-append --junitxml=junit/test-results.xml
         ls
 
@@ -58,5 +59,6 @@ runs:
         set TF2ONNX_SKIP_TFLITE_TESTS=${{ inputs.skip_tflite }}
         set TF2ONNX_SKIP_TFJS_TESTS=True
         set TF2ONNX_SKIP_TF_TESTS=False
+        set TF_USE_LEGACY_KERAS=True
         python -m pytest --cov=tf2onnx --cov-report=term --disable-pytest-warnings -r s tests --cov-append --junitxml=junit/test-results.xml
         ls

.github/workflows/keras_application_test_ci.yml

@@ -48,10 +48,10 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Run Tests (Py310-TF2.15)
+      - name: Run Tests (Py310-TF2.18)
         uses: ./.github/actions/keras_application_test
         with:
-          tf_version: '2.15.0'
+          tf_version: '2.18.0'
           python_version: '3.10'
           ort_version: '1.16.3'
           onnx_version: '1.16.1'
@@ -60,7 +60,7 @@ jobs:
         if: always()
         uses: actions/upload-artifact@v3
         with:
-          name: Test Results (Py310-TF2.15-ubuntu)
+          name: Test Results (Py310-TF2.18-ubuntu)
           path: ./**/test-results-*.xml
 
   Test_py37_with_tf1_15: # Do not change this name because it is used in Ruleset of this repo.

.github/workflows/keras_unit_test_ci.yml

@@ -47,10 +47,10 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Run Tests (Py310-TF2.15)
+      - name: Run Tests (Py310-TF2.18)
         uses: ./.github/actions/keras_unit_test
         with:
-          tf_version: '2.15.0'
+          tf_version: '2.18.0'
           python_version: '3.10'
           ort_version: '1.16.3'
           onnx_version: '1.16.1'
@@ -59,7 +59,7 @@ jobs:
         if: always()
         uses: actions/upload-artifact@v3
         with:
-          name: Test Results (Py310-TF2.15-ubuntu)
+          name: Test Results (Py310-TF2.18-ubuntu)
           path: ./**/test-results-*.xml
 
   Test_py37_with_tf1_15: # Do not change this name because it is used in Ruleset of this repo.

.github/workflows/pretrained_model_test_ci.yml

@@ -51,11 +51,11 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Run Tests (Py310-TF2.15-18)
+      - name: Run Tests (Py310-TF2.18-18)
         uses: ./.github/actions/pretrained_model_test
         with:
           os: 'ubuntu-latest'
-          tf_version: '2.15.0'
+          tf_version: '2.18.0'
           python_version: '3.10'
           ort_version: '1.16.3'
           onnx_version: '1.16.1'
@@ -66,7 +66,7 @@ jobs:
         if: always()
         uses: actions/upload-artifact@v3
         with:
-          name: Test Results (Py310-TF2.15-18-ubuntu)
+          name: Test Results (Py310-TF2.18-18-ubuntu)
           path: ./**/test-results-*.xml
 
   Test_py37_with_tf1_15: # Do not change this name because it is used in 'publish-test-results' section below.

.github/workflows/unit_test_ci.yml

@@ -51,11 +51,11 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Run Tests (Py310-TF2.15-18)
+      - name: Run Tests (Py310-TF2.18-18)
         uses: ./.github/actions/unit_test
         with:
           os: 'ubuntu-latest'
-          tf_version: '2.15.0'
+          tf_version: '2.18.0'
           python_version: '3.10'
           ort_version: '1.16.3'
           onnx_version: '1.16.1'
@@ -66,7 +66,7 @@ jobs:
         if: always()
         uses: actions/upload-artifact@v3
         with:
-          name: Test Results (Py310-TF2.15-18-ubuntu)
+          name: Test Results (Py310-TF2.18-18-ubuntu)
           path: ./**/test-results-*.xml
 
   Extra_tests:

tests/keras2onnx_unit_tests/conftest.py

@@ -13,6 +13,12 @@
 K = keras.backend
 
 
+def is_keras_3():
+    if hasattr(keras, '__version__'):
+        return keras.__version__.startswith("3.")
+
+    return False
+
 @pytest.fixture(scope='function')
 def runner():
     np.random.seed(42)
@@ -25,10 +31,15 @@ def runner():
     def runner_func(*args, **kwargs):
         return run_onnx_runtime(*args, model_files, **kwargs)
 
-    # Ensure Keras layer naming is reset for each function
-    K.reset_uids()
-    # Reset the TensorFlow session to avoid resource leaking between tests
-    K.clear_session()
+    if is_keras_3():
+        import tf_keras
+        tf_keras.backend.reset_uids()
+        tf_keras.backend.clear_session()
+    else:
+        # Ensure Keras layer naming is reset for each function
+        K.reset_uids()
+        # Reset the TensorFlow session to avoid resource leaking between tests
+        K.clear_session()
 
     # Provide wrapped run_onnx_runtime function
     yield runner_func

tf2onnx/convert.py

@@ -328,7 +328,8 @@ def _rename_duplicate_keras_model_names(model):
     IMPORTANT: model may be edited. Assign model.output_names to old_out_names to restore.
     """
     old_out_names = None
-    if model.output_names and len(set(model.output_names)) != len(model.output_names):
+    if hasattr(model, "output_names") and model.output_names \
+        and len(set(model.output_names)) != len(model.output_names):
         # In very rare cases, keras has a bug where it will give multiple outputs the same name
         # We must edit the model or the TF trace will fail
         old_out_names = model.output_names