# ONNX017: unregistered-op

**Code:** `ONNX017`

**Name:** `unregistered-op`

**Severity:** error

**Category:** spec

**Target:** node

**Fixable:** No

## Message

No operator schema found for this op type and opset version.

## Suggestion

Check the op_type, domain, and opset version are correct.

## Details

No operator schema is registered for the given op_type and opset version
combination. This may indicate a typo in the op_type, an incorrect domain,
or a missing opset import.