Model Won’t Load

Symptoms:

Clicking a model in the Models tab does nothing
Notice bar says “Failed to load model: …”
Aim Tools page stays in the “no model loaded” state

Checklist

1. Is the file actually an ONNX file?

PowerAim accepts only .onnx. Verify:

File extension is .onnx
File size is reasonable (small models 5–20 MB, large 50–250 MB)
File isn’t 0 bytes (a failed download)

If you downloaded the file from a non-store source, re-download — corrupted ONNX files refuse to load.

2. Is the file in the right folder?

PowerAim looks in <install dir>\bin\models\. If the file is anywhere else, it won’t appear in the local list.

3. Is the architecture supported?

PowerAim is built around YOLOv8 ONNX (anchor-free, NCHW input, 1×3×H×W). Other architectures may fail to load. Specifically:

YOLOv5 ONNX usually works (PowerAim handles both anchor-based and anchor-free output)
YOLOv7 should work but isn’t officially tested
Non-YOLO ONNX (custom architectures) — likely fails

4. CUDA build trying to load on a non-NVIDIA system?

The CUDA build expects:

An NVIDIA GPU
The CUDA 12.x runtime installed on the system

If you have an AMD or Intel GPU and the CUDA build, PowerAim falls back to DirectML — but if CUDA itself crashes on load, the fallback never gets a chance. Switch to the DirectML build.

5. Test with a known-good model

Click any of the bundled Universal*.onnx files. They’re known to work. If even bundled models fail, the issue is environmental (.NET, VC++, ONNX Runtime) rather than the model.

6. Read the in-app log

Logs sidebar item. ONNX Runtime errors are written here verbatim — they usually say exactly what’s wrong:

Unsupported operator: ... → model uses a custom op PowerAim doesn’t support
Invalid input shape: ... → input shape isn’t what PowerAim expects
DXGI device removed → GPU driver crashed; reboot

7. Re-install prerequisites

If models fail with cryptic native errors (access violation, DllNotFound), reinstall:

.NET Runtime 10 (x64)
Visual C++ 2015-2022 Redistributable (x64)

Both must be x64. PowerAim does not work with x86 variants.

8. Switch DirectML / CUDA build

Settings → UI Settings → Switch to DirectML / CUDA. If one build refuses to load a model, the other might handle it. CUDA in particular is more permissive about non-standard ops.

Multi-class model class list is empty

If the model loads but the Target Classes dialog shows Class 0, Class 1, etc. instead of names — the model is missing the names custom metadata field. Either:

Re-export from Ultralytics: model.export(format="onnx") automatically writes names
Or live with the numeric IDs — they still work for filtering

“Invalid input shape” specifically

PowerAim expects [N, 3, H, W] (NCHW) where N=1 and 3 is RGB channels. If your model is NHWC, re-export with NCHW order:

model.export(format="onnx", dynamic=True, simplify=True)