How to fix "This module is blocked from loading into the Local Security Authority"

Question

I keep getting the pop-up in the title and don't know how to fix it. It's coming from a file called "mdnsNSP.dll" in a folder "Bonjour". Is it harmful?

Answer 1

The error message "This module is blocked from loading into the Local Security Authority" typically indicates that a specific module, in this case, mdnsNSP.dll from the Bonjour service, is being prevented from loading due to security policies or settings in Windows. This can happen for various reasons, including issues with the module itself or conflicts with security settings.

To address this issue, you can try the following steps:

1. Check for Malware: Ensure that the mdnsNSP.dll file is not a malicious version. Run a full system scan with your antivirus software to check for any threats.
2. Reinstall Bonjour: If you need the Bonjour service (often used for network discovery), consider uninstalling and then reinstalling it. This may resolve any issues with the mdnsNSP.dll file.
3. Update Windows: Ensure your Windows operating system is up to date, as updates can fix bugs and improve system stability.
4. Modify Local Security Policy: If you have access to the Local Security Policy editor, you can check the settings related to software restrictions and ensure that the Bonjour service is allowed to run. However, be cautious when modifying security settings.
5. Check Event Viewer: Look into the Event Viewer for any related error messages that might provide more insight into why the module is being blocked.

As for whether the file is harmful, mdnsNSP.dll is generally associated with Apple's Bonjour service, which is not harmful by itself. However, if the file has been modified or is located in an unexpected directory, it could pose a risk. Always ensure that files come from trusted sources.

If the problem persists after trying these steps, consider seeking further assistance from technical support or forums dedicated to Windows issues.