mdnsNSP.dll - This module is blocked from loading into the Local Security Authority

Do you use AirPlay or sync over Wi-Fi? If not then I don't think you need Bonjour at all.

tt2

exact same thing happened to me yesterday, repair shop had to reset to factory, phone fine on 18.2 now but is no longer recognized by itunes (from MS store), works fine on my wifes laptop (with itunes from MS store), havent tried dling form apple direct, but today i get the same popup, wish there was an easy alternative to get audiobooks onto my phone from PC.

Yes, uninstall iTunes and reinstall, then remove bonjour from Settings - Apps - Installed Apps and you'll find Bonjour. I used the registry method in a previous post and it fixed it for me and kept bonjour.

The windows store one bricked my iPhone 15 Pro when I figured it was best to have the latest iTunes. Big mistake. The old iTunes saved the day and had my backup (I back up my phone before updating as always).

Shame we have to just ignore but at least it’s an option on windows 11 to hide it 😅

Same problem here. Bonjour 3.1.0.1 was installed on this Windows 11 machine ~2015, but there seems to be a 2025 update. The DLL is from 2015. However, Bonjour.Resources was changed in 2025.

I think it has to do with the iCloud app/software installed since I removed iTunes etc. a long time ago. I will give it a try and uninstall Bonjour as I have not found any other ways around (exceptions) and hope that iCloud continues to work.

Bottom line: Only Apple can (must) fix this.

Have you had any issues with iTunes after uninstalling Bonjour?

I get this same issue when I had to move to iTunes from Apple and not the Microsoft app store when it bricked my iPhone updating to iOS 18.2. I’ve been ignoring the LSA message when it comes up every 2/3 days (actually get 2 identical messages at once). It does give the option to not show the message again but I don’t check it because I’d like to know if this will get fixed and if it is okay to keep ignoring the message.

I have been having the same problems. To use GRBForHim's terminology iTunes from the MS Store also bricked my iPhone whist updating to iOS 18.2.1 and it would not let me restore my phone. After reading several online articles I uninstalled iTunes and installed the Apple Devices app. I did a forced restart on my phone which then displayed the symbol telling me to plug the phone into my computer. This I did after starting the Apple Devices app. This app fortunately picked up on the Backup on my computer created by iTunes and after selecting Update and waiting quite a while my phone was back to somewhere near where it was before the original attempted update via iTunes. Several apps required a re-registration with the provider but overall I was relieved that I did not have to rack my brains to recall all the apps I had got used to using.

However, as turingtest2 says I was not impressed by with the Apple Devices app. In particular it did not enable me re-install the many Podcasts I had already downloaded onto my computer. As I had read that the Apple Devices app and iTunes will not sit along side one another I uninstalled the former and reinstalled the latter but this time the version from Apple's website.

This enabled me put the Podcasts back on my phone but I am now getting the message from Microsoft's Program Compatibility Assistant as per the head of this thread. I will live with this for a while at least.

I have also had warnings about disk space on my computer and I have traced this to the fact that the newly installed iTunes from Apple stores the backups from my phone in a different location to iTunes from the MS Store.

I have posted this in the hope that the history of my experience may be of help to others.

FWIW : here is what happened to me. I had NO current Apple products or software installed on my freshly built Windows 11 PC. Or so I thought. Got the Bonjour mdndnsp.dll blocking message as well (right after the 24H2 installatione). Turned out to be a Spotify plugin that was causing this behaviour on mine. Went to the installed apps and sure enought, somehow Bonjour was installed with Spotify? Just my 2cts if anyone (like me) was wondering what an Apple service was doing on my kit.

Thanks for the info. If there happens to be issues with it being uninstalled, how do you reinstall? Do you have to uninstall iTunes and then reinstall iTunes again to get it back?

I reverted the regedit change to how it was blank and uninstalled bonjour. Thank you for the heads up!

@Maddawg72: Spotify can connect to devices via AirPlay, which uses Bonjour for network discovery.