Unsupported ONNX opset version: 11
I'm following this guide to convert darknet to onnx. However, I'm facing the following error:

&quot;C:\Users\Scott\Anaconda3\envs\pytorch_yolov4\lib\site-packages\torch\onnx\symbolic_helper.py&quot;,
line 253, in _set_opset_version
raise ValueError(&quot;Unsupported ONNX opset version: &quot; + str(opset_version)) ValueError: Unsupported ONNX opset version: 11

What does this error mean and how to deal with it?

It looks like you have an old PyTorch version, probably PyTorch 1.2.
The docs here https://github.com/Tianxiaomo/pytorch-YOLOv4#4-pytorch2onnx recommend at least PyTorch 1.4.
