From what the message says, the framework doesn't support Sigmoid operations. However I looked into the repository for nncase (github.com/.../nncase) and it shows that sigmoid is supported, so maybe you are using an older version of nncase?
"Fatal: Not supported ONNX opcode: Sigmoid". This means that the tool ncc (the Nncase compiler) does not support the Sigmoid operation in your ONNX model. Replace the Sigmoid operation with an equivalent or supported operation that Nncase can handle.You can try modifying your model to use a different activation function, or preprocess the model using a tool like ONNX Graph Surgeon (GS) to remove or replace unsupported nodes.
