Missing example template preview images/videos in Safari

### Custom Node Testing

- [x] I have tried disabling custom nodes and the issue persists (see [how to disable custom nodes](https://docs.comfy.org/troubleshooting/custom-node-issues#step-1%3A-test-with-all-custom-nodes-disabled) if you need help)

### Expected Behavior

When selecting "Browse Templates" on MaOS/Safari, I expected to see the current list of example templates from the current git template repo along with their sample images/videos.

### Actual Behavior

The template window populates, but the sample image/video is just a file icon. It does work properly in Firefox. I have reset safari history and website data. I have redone the pip install dependancies.


### Steps to Reproduce

Git clone the repo (Installs v0.3.54)
pip Install dependancies (all requirements installed, including comfyui_workflow_templates-0.1.75)
Connect with safari.
Select Browse Templates

### Debug Logs

```powershell
Not aware of what debug logs would help.
```

### Other

_No response_

---

*This issue is transferred from: https://github.com/comfyanonymous/ComfyUI/issues/9727*

Original issue was created by @SquishedSquirrel at 2025-09-05T03:25:24.000Z

**Original Comments:**

@christian-byrne:

Can you open Web Inspector with Option+Command+I and show the network activity and if any errors exist in the terminal/logs (when opening the templates dialog for first time after refresh)? Search in network activity for `templates` if possible. Thank you.

@SquishedSquirrel:

Web inspector has a number of errors. One that stands out is:


`Failed to load resource: the server responded with a status of 404 (Not Found) http://127.0.0.1:8188/api/userdata/comfy.templates.json`

![Image](https://github.com/user-attachments/assets/4c04630d-213c-42ca-a382-20f1025cbb25)

If it makes any difference, my templates were installed via pip, so they are not present in the comfyui hierarchy. Still, it does work in FF and Chrome.

@SquishedSquirrel:

To confuse things even further, ONE time the previews loaded. Closed the example template window and reopened it, and they were gone, back to the file icon.

@jimmybrancaccio:

I thought I was the only one who might be experiencing this issue, but it appears not! 😝 I am using Safari Version 18.6 (20621.3.11.11.3). I checked in Firefox and it works fine there. Odd issue!

@mextex:

I have the same issue. Safari 18.5 does not show the thumbnails. Other Browsers (Chrome Version 113.0.5672.126, Firefox 137.0.2) show thumbnails as expected

@TheP4gan:

I have the same issue in chrome

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-6535-Missing-example-template-preview-images-videos-in-Safari-29f6d73d36508198a1bbf647e7ebdda7) by [Unito](https://www.unito.io)