Error converting object detection api model to tflite

• What is the top-level directory of the model you are using N/A
• Have I written custom code (as opposed to using a stock example script provided in TensorFlow): no
• OS Platform and Distribution (e.g., Linux Ubuntu 16.04): Ubuntu 16.04
• TensorFlow installed from (source or binary): binary
• TensorFlow version (use command below): v1.14
• Bazel version (if compiling from source):
• CUDA/cuDNN version: 10.0, 7.4.1
• GPU model and memory: Titan V, 12 GB
• Exact command to reproduce: tflite_convert --output_file converted.tflite --saved_model_dir /path/to/model

Describe the problem

I trained a SSDLite-MobilenetV2 model using the provided documentation in the Object Detection Api. Then I exported the model by running the export_tflite_ssd_graph. A pb and a pbtxt file were generated. Finally, I tried to convert the model to tflite format using the command mentioned above. However, I got the following error:

**Traceback (most recent call last):
File "/usr/local/bin/tflite_convert", line 11, in
sys.exit(main())
File "/usr/local/lib/python2.7/dist-packages/tensorflow/contrib/lite/python/tflite_convert.py", line 412, in main
app.run(main=run_main, argv=sys.argv[:1])
File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/platform/app.py", line 125, in run
_sys.exit(main(argv))
File "/usr/local/lib/python2.7/dist-packages/tensorflow/contrib/lite/python/tflite_convert.py", line 408, in run_main
_convert_model(tflite_flags)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/contrib/lite/python/tflite_convert.py", line 100, in _convert_model
converter = _get_toco_converter(flags)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/contrib/lite/python/tflite_convert.py", line 87, in _get_toco_converter
return converter_fn(**converter_kwargs)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/contrib/lite/python/lite.py", line 340, in from_saved_model
output_arrays, tag_set, signature_key)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/contrib/lite/python/convert_saved_model.py", line 239, in freeze_saved_model
meta_graph = get_meta_graph_def(saved_model_dir, tag_set)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/contrib/lite/python/convert_saved_model.py", line 61, in get_meta_graph_def
return loader.load(sess, tag_set, saved_model_dir)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/saved_model/loader_impl.py", line 197, in load
return loader.load(sess, tags, import_scope, **saver_kwargs)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/saved_model/loader_impl.py", line 350, in load
** saver_kwargs)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/saved_model/loader_impl.py", line 275, in load_graph
meta_graph_def = self.get_meta_graph_def_from_tags(tags)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/saved_model/loader_impl.py", line 251, in get_meta_graph_def_from_tags
" could not be found in SavedModel. To inspect available tag-sets in"
RuntimeError: MetaGraphDef associated with tags set(['serve']) could not be found in SavedModel. To inspect available tag-sets in the SavedModel, please use the SavedModel CLI: saved_model_cli

EDIT: the same problem occurs after updating to TF 1.14 with the last API version.