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title: API Designer Troubleshooting
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# API Designer Troubleshooting

> For the full documentation index, see: https://docs.mulesoft.com/llms.txt

This page describes common issues that sometimes occur when working in API Designer, along with
their causes and recommended troubleshooting steps.

## Preparing to publish status persists

While working in API Designer, these issues sometimes occur:

- The **Preparing to publish** dialog doesn’t complete when publishing to Exchange.

- API specifications don’t display validation errors, warnings, or suggestions.

- The API Console doesn’t render or remains blank.

- The browser console shows a `NetworkError` related to loading the `anypoint-als.js` library.

These issues typically occur when a required API Designer component fails to load due to network
restrictions.

API Designer relies on API Language Services, which is a background service, to enable validation
and rendering. In some environments, corporate firewalls, VPNs, or proxies can block or interrupt
the download of this component, preventing the editor from functioning correctly.

### Verification and diagnostics

To verify whether your network is correctly delivering the required resources:

- **Compare file delivery via cURL** Run this command and confirm the response is successful and
  that the file size is approximately 1.5 MB:

```bash
curl -I https://cdn.anypoint.mulesoft.com/artifacts/api-designer-ui/app/static/js/anypoint-als.01bd90ee2cb9622ee518fcb3e30c444e.js
```

#### Troubleshooting

To identify and resolve the issue:

- **Test outside restricted networks**: Try accessing API Designer without a corporate VPN or proxy.

- **Use a clean browser session**: Clear your browser’s cache and cookies, then reload the page.
  Alternatively, open a private or incognito window and disable browser extensions.

- **Try a different browser**: Switch to another browser, such as Chrome, Edge, Firefox, or Safari.

- **Check local security software**: Ensure antivirus or endpoint protection tools aren’t blocking
  background scripts or service workers.

## See Also

- [Known Issues](https://help.salesforce.com/s/issues)