Windows 10 Version 1909 and 1903 Optional Monthly Update Meant To Address Search Problems Causing Several Weird Bugs And Issues

The Windows 10 version 1909 and 1903 optional monthly update that arrived late last month was eagerly anticipated by Windows 10 OS users. It was packed with several feature additions and stability improvements. However, the new Cumulative Update has reportedly given rise to several new and weird issues, including system instability, slower boot-up time, erratic FPS, audio stutters, etc.

The non-security and optional Cumulative Update KB4535996 attempted to fix several bugs inside Windows 10 v1903 and v1909. The new Cumulative Update also referred to as C-Update, is meant for the Windows 10 May Update and the Windows 10 November Update. Among many different things, the update included a fix to address the Windows Search issues that many Windows 10 users were facing. Although the update has worked for a lot of users, there is an increasing number of complaints about new issues cropping up after successfully installing the Cumulative Update KB4535996.

Issues Caused By non-Security And Optional Cumulative Update KB4535996:

Some Windows 10 OS users, particularly System Administrators, are reporting that Sign Tool (SignTool.exe), which is a command-line tool to digitally verify or sign files, crashes after installing this particular update. Several people have reported in the Feedback Hub posts confirming that Microsoft’s Sign Tool (SignTool.exe) may crash with error message 1073741502.

The second most concerning issue is regarding Windows 10 Boot. A growing Reddit thread acknowledges the latest Cumulative Update installs correctly. However, in several cases, it can cause abrupt boot failures. Even if the Windows 10 booting process initiates correctly, the KB4535996 update can progressively increase boot times.

In Microsoft’s answer forum, Feedback Hub and Reddit, a few users have reported that their Windows 10 computers boot slowly or fail to boot after the update is installed. For some users, the patch leads to a reboot loop. The only way to end the boot loop is to head over the Safe Mode and make Windows 10 roll back the patch. Some users have recommended uninstalling the patch from the Settings app. Doing so will reportedly ensure Microsoft won’t offer it to the user again unless the user manually rechecks for updates.

Some of the other uncommon problems caused by Cumulative Update KB4535996 is intermittent framerate drops. In other words, the update is reportedly causing FPS drops while playing games. A few others have added that the update can also cause sudden audio stuttering within games. Interestingly, a few users have tested the issue, and note that the update may cause about a 10 percent drop in FPS.

How To Address Issues Caused By Cumulative Update KB4535996?

Incidentally, uninstalling the Cumulative Update KB4535996 is fairly easy. Moreover, uninstalling the update reverts the system to normal. Windows 10 OS users suffering from any or all aforementioned issues are advised to uninstall the KB4535996 update and check if the issues are resolved.

It is important to note that KB4535996 is an optional update for Windows 10 version 1909 and 1903. This means it won’t automatically be suggested to users of other versions of Windows 10. However, the OS users can still manually click on the ‘Download and install’ option to access, download and install the update. Additionally, there are offline installers for the update.

Microsoft has to officially acknowledge any of the abovementioned issues that are being allegedly caused by Cumulative Update KB4535996. Hence, there are no official fixes that can address any of the issues. Simply put, users are advised to use the ‘Deferred Updates’ option to delay installing the KB4535996 update.

Alap Naik Desai


A B.Tech Plastics (UDCT) and a Windows enthusiast. Optimizing the OS, exploring software, searching and deploying solutions to strange and weird issues is Alap's main interest.