How to fix the Bonjour mdnsNSP.dll - This module is blocked from loading into the Local Security Authority?

Question

I have at least a three programs that use Bonjour including my local network printers. The Bonjour mdnsNSP.dll is being blocked by the Local Security Authority. My computer in running Windows 11 Pro version 25H2 OS build 26200.8457. How can I fix this problem so my programs and hardware work properly?

Answer 1

Hi!

LSA is enabled starting with some versions of Windows 11. It blocks unsigned DLLs or outdated services. You should update the services that use Bonjour.

In the case of iTunes, you can download a more up-to-date version from the website and install it. This will update the app. You can repeat this procedure for several apps that use Bonjour. In the case of printers, check if there is a new driver version for them.

Also check if Windows is fully updated in Settings > Windows Update > Check for updates.

Answer 2

The answer was helpful enough for me to research & find the new app from Apple "Bonjour Printer Services Installer". I made sure all my programs were up to date, uninstalled the old Bonjour and installed the newly found app from Apple.

Answer 3

I was able to resolve my problems by making sure all my programs were up to date, uninstalling the old version of Bonjour and installing the new application "Bonjour Printer Services Installer" from Apple. Now everything is working properly. Thanks!