ONNX export yields Error !

Dear MathWorks Deep Learning Toolbox Team:

Hi, I tried to use exportONNXNetwork, I ran this part of code, but i saw this error, could you help me pls?!

Usage example:

%% Export to ONNX model format

net = squeezenet;

filename = 'squeezenet.onnx';

exportONNXNetwork(net,filename);

-------------------------------------

this error appear:

Error using nnet.internal.cnn.onnx.onnxmex

Invalid MEX-file

'C:\ProgramData\MATLAB\SupportPackages\R2019b\toolbox\nnet\supportpackages\onnx\+nnet\+internal\+cnn\+onnx\onnxmex.mexw64':

A dynamic link library (DLL) initialization routine failed.

Error in nnet.internal.cnn.onnx.ModelProto/writeToFile (line 50)

ModelPtr = onnxmex(int32(FuncName.EnewModelProto));

Error in nnet.internal.cnn.onnx.exportONNXNetwork (line 37)

writeToFile(modelProto, Filename);

Error in exportONNXNetwork (line 40)

nnet.internal.cnn.onnx.exportONNXNetwork(Network, filename, varargin{:});

Error in Untitled (line 5)

exportONNXNetwork(net,filename)

[cui,xingxing]

Matlab2021a also encountered a similar problem, restarting the matlab software restart still error

------------------------------------------------------------------------

net = resnet18();
exportONNXNetwork(net,'resnet18.onnx')

Error using nnet.internal.cnn.onnx.onnxmex

Invalid MEX-file 'C:\ProgramData\MATLAB\SupportPackages\R2021a\toolbox\nnet\supportpackages\onnx\+nnet\+internal\+cnn\+onnx\onnxmex.mexw64': 找不到指定的模块。

Error in nnet.internal.cnn.onnx.ModelProto/writeToFile (line 52)

ModelPtr = onnxmex(int32(FuncName.EnewModelProto));

Error in nnet.internal.cnn.onnx.exportONNXNetwork (line 38)

writeToFile(modelProto, Filename);

Error in exportONNXNetwork (line 38)

nnet.internal.cnn.onnx.exportONNXNetwork(Network, filename, varargin{:});

[David]

On Mac OS using Matlab 2021a I get:

>> exportONNXNetwork(trainedNetwork_1,'ONNXThumbs.onnx')

Error using nnet.internal.cnn.onnx.onnxmex

Unexpected Standard exception from MEX file.

What() is:Failed to load ONNX Shared library.

..

Error in nnet.internal.cnn.onnx.ModelProto/writeToFile (line 52)

ModelPtr = onnxmex(int32(FuncName.EnewModelProto));

Error in nnet.internal.cnn.onnx.exportONNXNetwork (line 38)

writeToFile(modelProto, Filename);

Error in exportONNXNetwork (line 38)

nnet.internal.cnn.onnx.exportONNXNetwork(Network, filename, varargin{:});

[Adrià López Escoriza]

Same, the bug report does not seem solve the issue in MacOS

Answer 1

[Jon Cherrie]

It looks like you are hitting this bug:

• Error when using functions for importing or converting ONNX or Caffe models on Windows
• https://www.mathworks.com/support/bugreports/2465087

There is a workaround listed in that bug report.

Answer 2

[Neelanjana Pal]

I also got the same issue but restarting the system solved my problem

[Hossein Khodabakhshi]

I have this issue too. Sometimes by restarting Matlab, it is solved. Does anybody have an idea to solve this issue permanently?

[cui,xingxing]

Use the version onnx importer and exporter updated on March 10, 2021, regardless of restarting matlab or win10 system, this kind of problem cannot be solved

It is strongly recommended that MathWorks Deep Learning Toolbox Team strengthen its (importONNXFunction, exportONNXNetwork) robustness and generalization

[Ting Su]

The cause of R2021a is that the bin folder created under C:\ProgramData\MATLAB\SupportPackages\R2021a\bin\win64\ is not recognized as a system path.

The following command should help.

mv C:\ProgramData\MATLAB\SupportPackages\R2021a\bin\win64\onnxpb.dll C:\ProgramData\MATLAB\SupportPackages\R2021a\toolbox\nnet\supportpackages\onnx\+nnet\+internal\+cnn\+onnx\

[cui,xingxing]

@Ting SuAfter copying onnxpb.dll, it can work now, thank you very much!