SageAttention or Triton import failure: match the platform and build combination

Symptoms and scope

A missing Python module, a missing Triton dependency and a Windows _fused DLL failure occur at different layers. Upgrading every dependency together is not a targeted repair.

Error fragments for search; IDs, values and filenames may vary:

No module named 'triton'
No module named 'sageattention'
DLL load failed while importing _fused

Source-supported context

SageAttention documents different hardware and dependency prerequisites for its implementations. ComfyUI issue #11739 reports a Windows _fused failure; one report does not establish that every current Windows build is unsupported. Source 1 Source 2

Cases to distinguish

1. The module is absent from this instance's Python environment.

2. The package exists but compiled kernels, Torch ABI, driver or runtime libraries do not match.

3. The selected acceleration implementation does not support the chosen device backend.

Diagnostic sequence

The sequence below is an editorial procedure based on the cited context, not a diagnosis already confirmed for your environment.

Step 1. Capture the actual module at the bottom of the full traceback, distinguishing ModuleNotFoundError from a native-library load failure.

Step 2. Compare the node's required SageAttention version with Python, Torch and GPU details as one compatibility set.

Step 3. Test an ordinary attention path only if the node officially permits it. Keep the original settings; do not invent replacement class names.

Step 4. Install or rebuild in a recoverable copy using a supported upstream method, then record the complete dependency combination.

Completion check

The same interpreter imports the module, node startup succeeds and a small task reaches and completes attention computation.

Limitations and cautions

A same-named package is not proof of trusted origin or compatible kernels. This guide does not supply unverified Windows wheels or promise the author's benchmark speed on your hardware.

Original sources

• SageAttention README — original record checked 2026-09-21.
• SageAttention fused DLL import failure — original record checked 2026-09-21.

Localization prepared: 2026-09-22. The source-check dates above were inherited from the existing article; this translation does not claim they were all rechecked today. No GPU run, minimum-memory measurement or runtime guarantee is supplied.

Related troubleshooting and guides

• xFormers is installed but unavailable: inspect its native extension and operators
• DLL load failed: identify the native extension instead of downloading loose DLLs
• ModuleNotFoundError in ComfyUI even though the package is installed