onnx network import fails

I'm trying to import an ONNX network created with pytorch (using opset 9).

I use the following command

net = importONNXNetwork('cql_policy_ep5_opset9.onnx','OutputLayerType','classification')

but this returns the error:

Unable to resolve the name nnet.internal.cnn.onnx.NodeTranslationPlacholder.

Error in nnet.internal.cnn.onnx.translateGemm (line 27)

issues = [issues nnet.internal.cnn.onnx.NodeTranslationPlacholder(node,...

Error in nnet.internal.cnn.onnx.translateONNX (line 145)

[layer, layerIssues] = nnet.internal.cnn.onnx.translateGemm(thisNode,initializerDimMap,initializerRawDataMap,LayerName,ImportWeights, inputLayerTypeEnum,

OpsetVersion);

Error in nnet.internal.cnn.onnx.importONNXNetwork (line 11)

[LayersOrGraph, translationIssues] = nnet.internal.cnn.onnx.translateONNX(modelProto, OutputLayerType, UserImageInputSize, true);

Error in importONNXNetwork (line 52)

Network = nnet.internal.cnn.onnx.importONNXNetwork(modelfile, varargin{:});

Any ideas how to fix this?

Thanks