What on earth does this article title mean? Glad you asked! KIR stands for Known Issue Rollback. Once a Windows 11 PC gets the cited KB installed, it may not run properly if booted into Safe Mode (no networking). MS suggests in its Known Issues discussion  that users boot into Safe Mode with Networking. This avoids looping Explorer crashes that otherwise cause screen flickering. Hopefully, the title now makes sense. KB5012643 Safe Mode bug gets KIR means MS will automatically apply a rollback of the offending feature to PCs that tag WU servers. A reboot is required for the fix to do its thing.

When KB5012643 Safe Mode Bug Gets KIR, What Happens?

You can learn more about Known Issue Rollback in a Windows IT Pro Blog post from March 2021. It’s entitled “Known Issue Rollback: Helping you keep Windows devices protected and productive.” Here’s what this item states.  KIR “… is an important Windows servicing improvement to support non-security bug fixes, enabling us to quickly revert a single, targeted fix to a previously released behavior if a critical regression is discovered.” In simpler terms, MS can tell WU to back out individual update package components.

Behind the scenes, policy settings either enable or disable code paths for “before” or “after” versions of code. If the “after” version is enabled, the update applies; if the “before” version is enabled, it reverts to the previous version.

Here’s how it works, quoted from the afore-linked post:

When Microsoft decides to rollback a bug fix in an update because of a known issue, we make a configuration change in the cloud. Devices connected to Windows Update or Windows Update for Business are notified of this change and it takes effect with the next reboot.

This is depicted in the lead-in graphic for this story.

Read the Post for More Deets…

There’s lots of great discussion in the Known Issue Rollback blog post. If you remain curious about its workings and capabilities, check it out. There’s also a much more technical exploration of KIRs from annoopcnair.com available for those who really want to get into the weeds. It covers details about managing and filtering group policies, and working with the KIR Policy Definitions Setup Wizard.  I didn’t know you could do that, so that makes this good stuff!

Recent reporting on the latest Patch Tuesday (April 13) includes mention of issues with completing Cumulative Updates (CUs). Thus, for example, check out this WindowsLatest item dated April 22. Entitled Watch out for these issues in Windows 11 KB5012592 & Windows 10 KB5012599 it mentions various errors would-be updaters could encounter. It also mentions two tried-and-true recovery/repair techniques, to which I’ll add a suggestion of my own. Thus, I provide three Windows Update repair tips for your consideration and use.

Here Are Three Windows Update Repair Tips

Note: all these tips work equally well for both Windows 10 and Windows 11. Use ’em with my blessing in the order provided. In my personal experience they’ll cover most update issues people are likely to encounter.

Tip1: Simple Reboot

That’s right. If a CU update fails to complete, the first strategy is to reboot the PC, and try again. Believe it or not, that is sometimes all that’s needed to get things working.

Tip2: Shift-Shutdown

If you hold down the Shift key while you select the Shutdown option in Windows 10 or 11, it forces what’s sometimes called a “full shutdown.” This forces Windows to close all opened apps and applications. It also logs out any logged-in accounts. At the same time, a full shutdown performs neither a hybrid shutdown nor will it hibernate your PC.

Hibernation saves open documents and running applications to the %systemdrive% and copies them back into RAM upon restart, to speed that process along and let you pick up where you left off. That’s NOT desirable when fixing WU issues.

A hybrid shutdown hibernates the kernel session (what the OS is doing) and shuts down everything else. This supports Fast Boot capabilities on the subsequent reboot process to speed it up. It’s enough like hibernation that it too, is NOT desirable when fixing WU issues.

Tip3: Reset WU

Although the tutorial “Reset Windows Update…” appears on TenForums, it works equally well for Windows 11. Basically, it involves running a batch file that stops all update related services, resets all the update related registry keys, then restarts all the update related services it stopped. Surprisingly, it works like a charm. I routinely keep this batch file on many of my Windows 10 and 11 desktops. As it has worked for me both long and well, so it can also do for you.

If None of the Above Works, Then What?

Alas, in some cases, none of the aforementioned fixes will work. Next thing I’d consider would be an in-place repair install (covered in this equally handy tutorial). After that, more dire measures including a clean install and/or a trip to the shop might be warranted. In my 30-plus years of “messing with Windows” that has happened to me exactly twice. One of these occurrences happened less than two weeks ago (see this post for details). Odds are, therefore, it shouldn’t happen to you. Fingers crossed!  One of them was pretty recent, after all…

I must report that my various efforts to get from Beta build 22000.588 to Dev channel build 22581 have gone nowhere. Hence my title “Beta Promotion Difficulties Continue,” to punctuate my lack of progress. I did, however get a more informative error message from one of those attempts (see item 3 below), as shown in the lead-in graphic above.

Attempts Undertaken, as Beta Promotion Difficulties Continue

Here’s a list of all of the fixes I’ve tried in attempting to overcome this increasingly vexing hurdle (of which exactly  none have worked):

1. Simple repetition of the WU update/upgrade process (2 or 3 times, most automatic). I’ve now paused updates for a week to save time and energy.

2. Unplug all non-essential peripherals (an mSATA SSD inside a Sabrent USB 3 enclosure in this case).

3. Use setup.exe from the UUPdump.net website-based ISO for Build 22581.1. It didn’t work, but did provide the more informative error message shown in the lead-in graphic for this story.

4. Remove .NET 3.5 and all related Windows 11 features, and try again. Greatly speeded up the update and install processes, but produced the same outcome as the preceding item.

5. Run dism /online /cleanup-image /restorehealth and then sfc /scannow. No joy there, either.

So far, in fact, I’m getting exactly nowhere. Sigh.

What’s Next?

I supposed I could try a clean install of Windows 11 from the aforementioned UUPdump.net ISO. But recent reports of install problems (in completion, and in the state of Windows 11 after the fact) give me pause. I don’t think I want to go there just yet.

According to other advice tied to the 0XC1900101 – 0X30018 error code, I could also try some or all of the following:

1. Reset Windows Update components. The TenForums tutorial on that topic includes a handy-dandy batch file that also works on Windows 11.

2. Disable antivirus — in this case Windows Defender. This is working on my other X380 Yoga, so I wouldn’t expect it to help here.

3. My BIOS is up-to-date already and I’m not aware of running any “problematic applications.”

You can get advice galore at stories such as How to Fix Update Error 0xc1900101-0x30018 in Windows 10 (HowtoEdge.com) and others of that ilk. For the moment I’m not inclined to spend more time chasing rabbits and rainbows.

What, Then?

My current plan is to wait for the next Dev Channel build to appear (which it should do, if not this week, then next week for sure). At that point, I’ll try again — and hope for a successful outcome. At the moment I’ve spent more than enough time. I’m content to take a time-out and wait for another try. . .