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
• CLI 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 your -i flags in the CLI (or your run() inputs in the app) match this order.

Format-Specific Issues

PyTorch Exported Program (.pt2)

• Requires PyTorch 2.1+
• 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)

TorchScript (.pt): Deprecated

• TorchScript support will be removed in a future release
• Some dynamic control flow is not supported
• Consider migrating to Exported Program (.pt2)

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