Model Conversion Issues

This page covers issues you may encounter when uploading and converting models with ZETIC Melange.

Unsupported Operations

Symptoms:

• Model upload fails on the Melange Dashboard
• Dashboard reports "Unsupported operation" or "Conversion failed"

Solutions:

Simplify ONNX Models

Use onnx-simplifier to reduce complex subgraphs:

pip install onnxsim
onnxsim input_model.onnx output_model.onnx

Check ONNX Opset Version

Export with a commonly supported opset (opset 12-13 recommended):

# PyTorch to ONNX
torch.onnx.export(model, input, "model.onnx", opset_version=13)

# TFLite to ONNX
python -m tf2onnx.convert --tflite model.tflite --output model.onnx --opset 13

Avoid Dynamic Shapes

Export with static input dimensions:

# YOLO example
model.export(format="onnx", dynamic=False, imgsz=640)

Input Shape Mismatches

Symptom: Model compiles but produces incorrect results or crashes at inference time.

Cause: The input shapes provided during upload do not match the shapes used during inference.

Solutions:

• Use Netron to inspect your model's expected input shapes.
• Ensure the .npy input files match the model's expected dimensions exactly.
• Verify input data types (typically Float32).

Input Order Errors

Symptom: Model produces garbage results despite correct shapes.

Cause: Inputs are provided in the wrong order.

Solution: Verify input order using Netron:

1. Open your model in Netron.
2. Check the top-most input node: this is Index 0.
3. The next input node is Index 1, and so on.
4. Ensure the inputs you upload on the Dashboard (and your run() inputs in the app) follow this order.

Format-Specific Issues

PyTorch Exported Program (.pt2)

• Requires PyTorch 2.9+
• Some custom operators may not be supported by torch.export
• Try tracing with simpler inputs if export fails

ONNX (.onnx)

• Use onnxsim to simplify before upload
• Check for unsupported custom operators
• Verify opset version compatibility (12-13 recommended)

Compilation Status: Failed

Symptom: Model shows "Failed" status on the Dashboard.

Solutions:

1. Check the error message on the Dashboard for specific details.
2. Verify your model file is not corrupted.
3. Try re-exporting the model with a simpler configuration.
4. Contact contact@zetic.ai with your model file for support.

Still Having Issues?

• Check Common Errors for general issues
• Join the Discord community
• Email contact@zetic.ai with your model file for direct support