
The KB4515384 Cumulative Update for Windows 10, version 1903 is causing audio quality downgrade issues in multiple games according to numerous user reports.
For some, the issue is noticeable in games such as Overwatch, Apex Legends, WoW Classic, and PlayerUnknown's Battlegrounds, while for others in all games the sound is very low volume and it seems to be muffled.
While Microsoft has not yet acknowledged the issue on the page of the KB4515384 Cumulative Update or the Windows Release Health Dashboard and an official solution is not yet available, some fixes have already been suggested in online forums.
These range from switching the Windows Audio format to 16 bit, 44100 Hz (CD quality), toggling all Environment effects on and off, to uninstalling the audio device's drivers and using the Windows default ones.
However, seeing that these solutions are hit and miss, with some reporting that they worked while others say that trying one or more of them didn't help at all, users should uninstall the update to regain audio quality as a short-term resolution.
Before uninstalling KB4515384 Cumulative Update, you should know that you would also be removing an important number of security fixes for multiple products from Microsoft Edge, Internet Explorer, and Windows Kernel to Windows Media, Windows Fundamentals, Windows Authentication, as well as a number of protections against a new subclass of speculative execution side-channel vulnerabilities.
Uninstalling the KB4515384 update
If you are willing to trade a security downgrade over increased audio quality in your games, follow the procedure described below to remove the KB4515384 update.
Microsoft says in the update's details from the Microsoft Update Catalog that KB4515384 can be removed "by selecting View installed updates in the Programs and Features Control Panel."
The full step by step procedure needed to uninstall this update requires you to open Control Panel, go to Programs > Programs and Features, and click on View installed updates in the left sidebar.
Next, right-click on the KB4515384 update's entry in the list and confirm when asked if"Are you sure you want to uninstall this update?". All that's left to do is to click 'Yes' when asked and restart your device.
Search and start menu issues
Users are also reporting that the Windows 10 search feature is still broken, with some of them also stating that Windows Search doesn't start at all after installing the KB4515384 cumulative update.
Microsoft acknowledged the problems on September 11 and has added a new known issue to the Windows Release Health Dashboard stating that "Some users report issues related to the Start menu and Windows Desktop Search."
This issue impacts Windows 10, version 1903 users and Microsoft is "presently investigating and will provide an update when more information is available."

Microsoft also provides several suggestions that could fix the search problems, an issue very similar to a previously fixed one where Cortana had high CPU usage or sudden CPU spikes and searching did not return any results with the release of the KB4515384 cumulative update.
Users are encouraged by Microsoft to send feedback using the Feedback Hub if the provided solutions did not fix their problems.
H/T Windows Latest
Comments
Maelish - 3 years ago
There is a lesser known bug in 1903. It breaks the TAPI interface for ALL voice modems. Really annoying when that's how you control landline spam or voicemail.
serghei - 3 years ago
Haven't been able to find any other reports. Do you know what causes it and if there are other people affected by it? Also, did you report it to Microsoft and did you get an answer from them?
If you don't want to use the Feedback Hub app, you can try reaching out to https://twitter.com/windowsupdate, they seem to be quite active lately :)
Yojji - 3 years ago
Funny how it always seems to be gamers that get hit by Microsoft's negligent testing. They really need to get rid of these shove-it-down-your-throat updates if they're not going to do any real SQA.