System information (version)

• OpenCV => 3.4.1
• Operating System / Platform => Mac OS , Ubuntu 16.04
• Compiler => cmake

Detailed description

When I use the newest version of tf_text_graph_ssd.py to generate graph txt file for my own tensorflow model, I keep getting this error:

Traceback (most recent call last):
File "tf_text_graph_ssd.py", line 138, in
assert(graph_def.node[0].op == 'Placeholder')
AssertionError

I have trained two models using ssd_mobilenet_v1 and ssd_mobilenet_v2.
I notice that the newest tf_text_graph_ssd.py should support ssd_mobilenet_v2 but it does not work so I went back to train using ssd_mobilenet_v1. And still, the tf_text_graph_ssd.py showed the same error.
After that, I went back to the previous version of tf_text_graph_ssd.py and it successfully generate the pbtxt for ssd_mobilenet_v1 model.
Please take a look to the new version, I honestly don't know why it does not work while the other Issue post says it worked. Thank you!