I found the solution. This page tells that only onnx version 1.2.1 is supported. After downgrading onnx from 1.5.0 to 1.2.1, all worked fine.
I found the solution. This page tells that only onnx version 1.2.1 is supported. After downgrading onnx from 1.5.0 to 1.2.1, all worked fine.