Exporting graph with number_of_stages=1 gives TypeError

Hi, I'm trying to run faster_rcnn_inception_resnet_v2_atrous_oid_v4_2018_12_12 pretrained model from the model zoo and obtain RPN boxes. I'm setting number_of_stages = 1 in the pipeline.config file, but when I run export_inference_graph.py, I get the following error:

python ../models/research/object_detection/export_inference_graph.py --pipeline_con fig_path ./pipeline.config --trained_checkpoint_prefix ./model.ckpt --output_directory ../new_graph_0.2_0.4_first_stage /usr/lib/python2.7/dist-packages/h5py/__init__.py:36: FutureWarning: Conversion of the second argument of issubdtype from floattonp.floatingis deprecated. In future, it will be treated asnp.float64 == n
p.dtype(float).type. from ._conv import register_converters as _register_converters Traceback (most recent call last): File "../models/research/object_detection/export_inference_graph.py", line 150, in <module> tf.app.run() File "/usr/lib/python2.7/dist-packages/tensorflow/python/platform/app.py", line 125, in run _sys.exit(main(argv)) File "../models/research/object_detection/export_inference_graph.py", line 146, in main write_inference_graph=FLAGS.write_inference_graph) File "/home/ditochi/yandexsdc/Experiments SSD/models/research/object_detection/exporter.py", line 453, in export_inference_graph write_inference_graph=write_inference_graph) File "/home/ditochi/yandexsdc/Experiments SSD/models/research/object_detection/exporter.py", line 357, in _export_inference_graph graph_hook_fn=graph_hook_fn) File "/home/ditochi/yandexsdc/Experiments SSD/models/research/object_detection/exporter.py", line 325, in _build_detection_graph output_collection_name=output_collection_name) File "/home/ditochi/yandexsdc/Experiments SSD/models/research/object_detection/exporter.py", line 306, in _get_outputs_from_inputs output_collection_name) File "/home/ditochi/yandexsdc/Experiments SSD/models/research/object_detection/exporter.py", line 209, in add_output_tensor_nodes detection_fields.detection_classes) + label_id_offset TypeError: unsupported operand type(s) for +: 'NoneType' and 'int'

I'm using Tesorflow 1.13, python 2.7, Ubuntu 18.04