title: DNN library is not found ssd_mobile_net_v2 in Colab
body: <p>I'm training a hand detection model with Tensorflow and I have a problem.</p>
  <p>This is the code to train the model:</p>
  <pre><code>!cd RealTimeObjectDetection/RealTimeObjectDetection &amp;&amp; python Tensorflow/models/research/object_detection/model_main_tf2.py --model_dir=/content/RealTimeObjectDetection/RealTimeObjectDetection/Tensorflow/workspace/models/my_ssd_mobnet --pipeline_config_path=Tensorflow/workspace/models/my_ssd_mobnet/pipeline.config --num_train_steps=5000
  </code></pre>
  <p>I have this error:</p>
  <pre><code>Node: 'ssd_mobile_net_v2_fpn_keras_feature_extractor/model/Conv1/Conv2D'
  DNN library is not found.
       [[{{node ssd_mobile_net_v2_fpn_keras_feature_extractor/model/Conv1/Conv2D}}]] [Op:__inference__dummy_computation_fn_15081]
  </code></pre>