Windows 11 wrecks localhost functionality with latest cumulative update

[Alfonso Maruccia]

What just happened? Microsoft continues its tradition of making Windows a little more cumbersome with each monthly patch cycle. Following the October update, Windows 11 admins and developers are reporting broken localhost connections – prompting widespread complaints, quick rollbacks, and questions about how such a bug cleared Microsoft's testing.

The recent KB5066835 update for Windows 11 broke the operating system's localhost interface, prompting affected users and developers to uninstall the patch in an attempt to restore functionality. The exact number of impacted systems is unknown, but discussion forums are already flooded with complaints and help requests.

Localhost is a special network hostname that refers to the host system. It allows users to access network services running on the local computer while bypassing network interface hardware entirely. Since Windows 7, Microsoft has implemented localhost through the Http.sys component, which functions as a web server exclusive to Windows.

After installing KB5066835, users reported a series of issues with localhost. Requests for help quickly spread online, with sites like Stack Overflow and Super User locking multiple posts related to the KB5066835 incident due to repeated queries. Users experienced HTTP/2 protocol errors, failed connection attempts, and other localhost-related problems in development environments such as Visual Studio.

Some developers were able to restore functionality by uninstalling KB5066835, while others also removed the September update KB5065789 to resolve the issue. Notably, freshly installed Windows instances that received the latest patches directly did not appear to be affected.

In some cases, a temporary fix requires disabling HTTP/2 protocol support by manually editing the Windows Registry. Other potential workarounds include turning off Windows' native hypervisor (Hyper-V), the IIS server functionality, the Windows Process Activation Service, and both .NET Framework 3.5 and 4.8 before attempting to uninstall the KB5066835 update.

October's Patch Tuesday included several security fixes as well as improvements for Chromium-based browsers, PowerShell, Windows Hello, and more. However, Microsoft does not mention http.sys or localhost anywhere in the release notes, suggesting an unknown conflict between KB5066835 and certain system configurations.

Elsewhere, Microsoft also released the final cumulative update for Windows 10, marking the end of mainstream support for the legacy OS. The company has consistently described Windows 11 as the most secure, reliable, and capable operating system currently available for PCs. Yet, as the localhost outage demonstrates, Windows 11 is likely to introduce new frustrations for users, much like previous Windows editions.

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Windows 11 wrecks localhost functionality with latest cumulative update

 

[NumberNine]

What an invasive, absolute dumpster fire of an operating system.

 

[Burty117]

What an invasive, absolute dumpster fire of an operating system.

Since I’ve been using the internet (dialup days) to today, every windows version has this exact same comment in every comment section, of every corner of the internet.

Yet everyone still uses Windows, everyone still uses Microsoft software.

If it was truly that bad, everyone would have settled on alternatives by now, they haven’t, everyone is happy with Windows, because nobody wants to spend a few hours getting used to something else.

 

[TheBigT42]

What an invasive, absolute dumpster fire of an operating system.

There's no place like 127.0.0.1

 

[TheBigT42]

Since I’ve been using the internet (dialup days) to today, every windows version has this exact same comment in every comment section, of every corner of the internet.

Yet everyone still uses Windows, everyone still uses Microsoft software.

If it was truly that bad, everyone would have settled on alternatives by now, they haven’t, everyone is happy with Windows, because nobody wants to spend a few hours getting used to something else.

I have been using Microsoft Products since DOS 3.30 and calling BBSs.
I agree with NumberNine...Windows has become an invasive dumpster fire. It isn't about getting used to "something else". Micro$oft keeps rolling out these patches that either break things or remove functionality. Windows 11 is little more than spyware. That's why it is only 49% of Windows installations.

 

[dualkelly]

bUT wINdOwS iS bESt

 

[NotYourITguy]

I have plenty of reasons to dislike Windows, but anyone acting like another option is so much better needs a serious reality check. I find the majority of people with OS superiority complexes are incapable of seeing beyond their own needs.

Way too many core productivity apps simply don't exist for Mac and Linux. Anyone saying "just use something else" is fully ignorant to the human aspect of user experience. People use Adobe Creative Suite because it is the best available, not because anyone loves using it.

 

[maxxcool7421]

Microsoft is garbage, os and company. they need to go bankrupt and die and the execs need beating with barb wire bats

 

[p51d007]

Well, after all...consumers ARE the beta testers ya know. <wink>

 

[Thatsdisgusting]

Another batch of chatgpt code?

Sheeeit, seems like sci-fi writers were right altogether - we gonna have netkrash&datakrash provoked by AI

 

[Theinsanegamer]

I have been using Microsoft Products since DOS 3.30 and calling BBSs.
I agree with NumberNine...Windows has become an invasive dumpster fire. It isn't about getting used to "something else". Micro$oft keeps rolling out these patches that either break things or remove functionality. Windows 11 is little more than spyware. That's why it is only 49% of Windows installations.

People said the EXACT same thing about 10 a decade ago when 7 went out of support.

 

[DontMakeThemEasy]

One this is very true - it's very good this happening to average users, because then they can't say "oh my windows 11 is perfect it never dissapoints" (except M$ shills)

 

[Burty117]

I have been using Microsoft Products since DOS 3.30 and calling BBSs.
I agree with NumberNine...Windows has become an invasive dumpster fire. It isn't about getting used to "something else". Micro$oft keeps rolling out these patches that either break things or remove functionality. Windows 11 is little more than spyware. That's why it is only 49% of Windows installations.

This is almost word for word, any comment section when people moved from Windows 7 to Windows 10, word for word, "Windows 10 is just spyware trash" yada yada yada.

I asked before and I'll ask again, why are you using Windows if it's an "invasive dumpster fire"?

 

[Xelions]

Real programmers/hackers/evil-geniuses don't use Windows so who gives a fu#$ about localhost breaking.

Besides that, still got Windows 10+7 and Linux variants so hoorah!

 

[0dium]

People said the EXACT same thing about 10 a decade ago when 7 went out of support.

I hated win 10 back then and I still hate it now despite using it for many years. Win11 is even worse.

 

[Burty117]

I hated win 10 back then and I still hate it now despite using it for many years. Win11 is even worse.

And the reason you still use it is?

 

[Anton Longshot]

People said the EXACT same thing about 10 a decade ago when 7 went out of support.

A somewhat different take: I LOVED 7 and installed the BETA as main OS on a new PC I built, and bought 7's final release (my first Windows OS I paid for since 95).
At some point I had to install 10 and it needed a bit of tinkering to remove unwanted trash and a third party program to restore the start menu to 7's functionality.
Besides that it runs ever-so-slightly smoother than 7 on my boxes ánd fully prevented the very rare bluescreen 7 sometimes suffered. So I've always been OK with 10.

Advertising Platform 11 is unacceptable to me and I will likely 'leave' soon.
Life can happen though so I'll admit there IS a véry slight possibility I'll give in and install it.

 

[TheBigT42]

People said the EXACT same thing about 10 a decade ago when 7 went out of support.

And they were correct then too. Now it is much worse.

 

[Ecurb]

I went Linux Mint and now opensuse several years ago. I run a win 10 vm for my financial software, but that is it.

I also have a windows 8.1 media center that still runs fine.

I use windows for specialty software that won't run anywhere else.

I don't miss the drama and flame wars around Microsoft but I like to stay aware and I enjoy the silliness of the Windows defenders.

 

[0dium]

And the reason you still use it is?

I play games. Easy as that

 

[oldcanadian]

Sadly, just got this garbage dumped upon me by Corporate.
Now have very fancy paperweight.
Can't even fart without the "God" password.

 

[Burty117]

I play games. Easy as that

So you don't hate Windows?

 

[0dium]

So you don't hate Windows?

If you have no other option, it doesn't mean you like it. Where's logic behind your comment?

 

[Burty117]

If you have no other option, it doesn't mean you like it. Where's logic behind your comment?

You have no other option with specific multiplayer games, of which, you can duel boot and use Windows exclusively for. But most games you can get running on Linux, a lot without even trying and just work these days.

Or is Microsoft a giant monopoly and there's no real competition in the desktop operating system market. Forcing everyone to use their OS regardless?

My point originally on this article though, the vast majority of people just use Windows to browse the web, store and view some photos and videos, maybe do some document or spreadsheet work, and that's about it, which all can be done on Apple or Linux OS's, yet we've not see any kind of mass migration, even though for the last 30 years, every Windows release comes with comments about the new version being a "dumpster fire"...

 

[nemen]

25h2 signed me out of all my apps and just the nonsense of getting passwords to sign back in was a headache. ive noticed little to no difference