Workflow no longer opens in latest ComfyUI version

### Expected Behavior

It should open.

### Actual Behavior

It doesn't open, nothing happens. Even month-old PNGs that have embedded workflows no longer open, so it's not a recent addition on my part.

These workflows work in `v0.3.28` but not `v0.3.29`.

### Steps to Reproduce

Try to open this .json file through the UI and you won't even get the popup asking you to install the missing custom nodes:
[Noob-AI.json](https://github.com/user-attachments/files/19813129/Noob-AI.json)

### Debug Logs

```powershell
There's nothing, it fails silently.
```

### Other

_No response_