Windows 10: Audio-/ Install issues with KB4556799

[German]Another small addendum to the Windows 10 Update KB4556799. The update was released on May 12, 2020, but seems to cause installation errors for some users. Other users run into audio issues after installation. Here is a short overview.


Update KB4556799 for Windows 10

Cumulative Update KB4556799 was released on patchday, May 12, 2020, and raises the OS build to 18362,836 (Windows 10 V1903) and 18363,836 (Windows 10 V1909). The update is available for Windows 10 version 1903, for Windows 10 version 1909, and for Windows Server version 1903 and Windows Server version 1909.

It contains quality improvements but no new operating system features. I reported about the changes and improvements in the blog post Patchday: Windows 10 Updates (May 12, 2020). Microsoft wrote at that time that no problems were known for this update. In the meantime, Microsoft has added the following text to the support article for update KB4556799.

We have seen social media and news reports related to various issues with KB4556799. We are actively engaged with customers who are reporting issues. To date, we have not seen widespread issues reflected in telemetry, support data, or customer feedback channels. We continuously investigate all customer feedback and are closely monitoring this situation.

According to Microsoft, these are probably only isolated messages, there is no apparent error pattern or accumulation of problems.

Installation error 0x800F081F

In the Microsoft Answers forum, the update is mentioned in this thead, and a user logged in with the message that the update fails with error 0x800f081f during installation. The error code 0x800F081F stands for CBS_E_SOURCE_MISSING, which means that the source files were not found.

Some time ago I had discussed the error code in the blog post Windows 10 V1909: Update KB4528760 drops error 0x800F081F. Microsoft has also published a support article associated with a .NET installation error. Microsoft provides information that a file or folder that is referenced by the update cannot be found.


In such cases you will first try to repair the system or the component store (see my blog post Check and repair Windows system files and component store). Microsoft's advice for Windows 10 users who have this issue is to use the Windows 10 installation media in question as the source for repair. Some advice can be found in this Microsoft article.

Also the problem that users are logged on to a temporary problem after the update installation and cannot access their data in the old profile is reported sporadically.

Audio problems after update installation

But more annoying is the error pattern with users who can successfully install the update KB4556799, but after installation they find that the audio output does not work anymore. On there is this thread which reports about audio issues with the 'latest Windows 10 update' on Realtek chips. Reinstalling the driver does not help. The advice in this thread is to turn off the sound enhancements in Realtek audio drivers. This is described in detail in this thread.

1. Go to the sound options in the control panel and select the Realtek speaker.

2. Go to Properties and then go to the Advanced tab, there uncheck Sound enhancements

If the change is confirmed via the OK button, the audio output should work again. However, there are people who claim that it didn't work.

In this comment to the German blog postPatchday: Windows 10-Updates (12. Mai 2020) a user also points out audio problems. Lenovo has posted the article Audio device missing or cannot find audio device – ThinkCentre M720s, M720t. There it says:

Audio suddenly does not function on the system, despite the Realtek audio driver being correctly installed. In Device Manager, a red X may be on the Sound Mixer, and Device Manager does not show Realtek Audio or Intel Display Audio devices under Sound, video and game controllers. Re-installing the Realtek audio driver does not restore sound function to the system. This may occur after Windows Update runs.

The solution to this problem is to update the Intel High Definition DSP driver in Device Manager. There is probably an updated version of the Intel driver.

Bleeping Computer  has collected in this article other problems reported with the update. All in all, there does not seem to be a critical accumulation of error clusters. 

Similar articles:
Patchday: Windows 10 Updates (May 12, 2020)
Windows 10 V1909: Update KB4528760 drops error 0x800F081F
Check and repair Windows system files and component store

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