This error occurs when an unexpected action name (`action`) is used in a XenForo add-on or a customized function. The root cause of the issue is that the `watch_no_email` action is being passed to the `setWatchState()` function in the `XFRM/Repository/ResourceWatch.php` file, but this function only expects `delete` and `watch` actions.
### Detailed Analysis of the Error
- **`XFRM/Repository/ResourceWatch.php at line 92`:** Here, the `setWatchState()` function does not recognize the `watch_no_email` action.
- **`XV\Entity\ResourceItem->setWatchResource()`:** This function is passing an action to `setWatchState()`, but the passed action (`watch_no_email`) is not supported.
- **`XV\Pub\Controller\ResourceVersion->actionDownload()`:** This occurs when attempting to set the watch state of a downloadable resource.
### Possible Solutions
1. **Check Add-on or Customization:**
- The `watch_no_email` action might originate from an add-on or custom function. Ensure that this action name is correct and supported by the `setWatchState()` function.
2. **Fix the Code:**
- Since the `watch_no_email` action is not recognized, you might need to either remove this action from the code or properly add it to the `setWatchState()` function.
- If `watch_no_email` is a custom action, you can add an additional condition in the `setWatchState()` function to handle this action appropriately.
3. **Use an Alternative Action:**
- If this action is unnecessary, consider replacing the `watch_no_email` action with a recognized action like `watch` or `delete`.
### Summary
To resolve this error, you'll need to investigate the source and purpose of the `watch_no_email` action. Replacing it with a recognized action or modifying the code to support this action could solve the problem. If this action is coming from an add-on or a customization, reviewing the relevant code is essential.
