Problem with Inference/Exporting Graph: ValueError Attempted to map inputs that were not found in grah_def[image_tensor:0]

System information

• What is the top-level directory of the model you are using: /tensorflow/models/research/object_detection/
• OS Platform and Distribution (e.g., Linux Ubuntu 16.04): 16.04
  -Have I written custom code: Yes (to create tfrecord files, see above)
• TensorFlow installed from (source or binary): N/A
• TensorFlow version (use command below): 1.12-.0-rc2
• Bazel version (if compiling from source): N/A
• CUDA/cuDNN version: 10.0
• GPU model and memory: GeForce GTX 980 Ti
• Exact command to reproduce: see below

Error Description

I created a custom tfrecord file for the object detection task and fine-tuned a pre-trained Kitti Resnet101 Faster RCNN network with "my" data. I exported the graph by using the following code:

python object_detection/export_inference_graph.py \
    --input_type=tf_record \
    --pipeline_config_path= {Path_to_Config_File_Used_In_Training} \
    --trained_checkpoint_prefix={Path_To_CKPT_FIle} \
    --output_directory=${Export_Directory}

The Model Analysis Reports starts with
Incomplete Shape followed by a large list of output statements.

I executed the inference with following command:

python -m object_detection/inference/infer_detections \
  --input_tfrecord_paths={Path_To_TfRecord_File} \
  --output_tfrecord_path={Path_To_Output_TfRecord_File}.tfrecord-00000-of-00001 \
  --inference_graph={Path_To_Exported_Directory_See_Above}/frozen_inference_graph.pb \
  --discard_image_pixels

However, I got the following error code:

Traceback (most recent call last):
  File "infer_detections.py", line 96, in <module>
    tf.app.run()
  File "/home/user/.local/lib/python3.5/site-packages/tensorflow/python/platform/app.py", line 125, in run
    _sys.exit(main(argv))
  File "infer_detections.py", line 74, in main
    image_tensor, FLAGS.inference_graph)
  File "/home/user/tensorflow/models/research/object_detection/inference/detection_inference.py", line 74, in build_inference_graph
    graph_def, name='', input_map={'image_tensor': image_tensor})
  File "/home/user/.local/lib/python3.5/site-packages/tensorflow/python/util/deprecation.py", line 488, in new_func
    return func(*args, **kwargs)
  File "/home/user/.local/lib/python3.5/site-packages/tensorflow/python/framework/importer.py", line 455, in import_graph_def
    ', '.join(missing_unused_input_keys))
ValueError: Attempted to map inputs that were not found in graph_def: [image_tensor:0]

I am struggling with this error for some days and do not know what is wrong. Does anybody know why this error appear? I only work with tfrecord data.

I appreciate every hint/remark/solution.

Thanks a lot in advance.