KB4601380 updates Windows 10 1909 to Build 18363.1411

Microsoft releases a new optional update i.e. KB4601380 featuring quality improvements and fixes for Windows 10 version 1909. Applying this non-security patch will generate a new registry “dfslogkey” at location HKEY_LOCAL_MACHINE/SOFTWARE/MICROSOFT/dfslog. To make this work, you must restart the DFSN service on your device. Apart from this, this will increase your OS Build to 18363.1411.

KB4601380 addresses a handful of bugs that used to occur every now and then. A few of them are – Error: 0x80070003, stop error 7E in nfssvr.sys, Work folder Sync error 0x8007017c, and others. In this tutorial, we have outlined all the changes along with ways to download and install this cumulative update to your computer. Let’s explore the key improvements in detail –

KB4601380 optional update version 1909

KB4601380 Windows 10 1909 Changelog

Here are the key changes on this non-security update for Windows 10 1909 users – 

  • Improves high memory and CPU utilization in Microsoft Defender for Endpoint.
  • Enhances functionalities like – data loss prevention and risk management solution on Microsoft 365 endpoints.
  • Resolves certain COM+ callout policies-related issue that is known to cause a deadlock while starting a few applications.
  • Resolves an issue wherein fonts render incorrectly.
  • Updates the SetWindowRgn API in Windows 10 so that users can easily maximize, minimize, or close a particular window.
  • Earlier, when users go to Settings > Accounts > Sign-in Options page, Windows Hello for Business (WHfB) Certificate Trust deployment faces a delayed opening due to some internal issues. They addressed this bug as well on Build 18363.1411.
  • Updates Windows Remote Management (WinRM) to resolve its sudden stop-working issue. 
  • Improves the Windows Management Instrumentation (WMI) service so that no heap leak issue occurs while applying time security settings to WMI namespace permissions.
  • Removes the history of previously used pictures from a user account profile.
  • Addresses an issue with screen rendering after opening games with certain hardware configurations.
  • Improves startup times for applications that have roaming settings when User Experience Virtualization (UE-V) is turned on.
  • Addresses an issue that prevents the Trusted Platform Module (TPM) from starting. As a result, TPM-based scenarios do not work.
  • Resolves a bug that restricts wevtutil from parsing an XML file.
  • Addresses a bug on x86-bit Microsoft Excel 365 version 2011. The application fails to start while enabling the SimExec feature of Defender Exploit Protection. Similarly, when you disable the SimExec exploit protection and enable the CallerCheck protection, the Excel stops working. 

Error Code Fixes

  • Works upon an issue with a stop error that occurs during Windows startup.
  • Resolves a bug that usually occurs while opening untrusted webpages on Microsoft Edge. The error is – “WDAG Report – Container: Error: 0x80070003, Ext error: 0x00000001” and starts appearing after installing the .NET update KB4565627.
  • Addresses a stop error 7E that occurs in nfssvr.sys on servers running the Network File System (NFS) service.
  • Works upon an anomaly that causes a Work Folder sync to fail on error code 0x8007017c if you have turned on On-Demand File Access.
  • Resolves a bug wherein a trusted MIT realm fails to obtain a Kerberos service ticket from Active Directory domain controllers (DC).
  • KB4601380 fixes a bug reporting no error when the Elliptic Curve Digital Signature Algorithm (ECDSA) generates invalid keys of 163 bytes instead of 165 bytes.

Internet Explorer and Registry Changes

  • Updates the default values of Internet Explorer registry keys to the following –
    • svcKBFWLink = “ ” (empty string)
    • svcKBNumber = “ ” (empty string)
    • svcUpdateVersion = 11.0.1000.

Microsoft will no longer update these values automatically in upcoming releases. 

  • No memory leak issues while using the Chinese language pack on Internet Explorer.
  • Adds a new key to the registry i.e. “dfslogkey“. You may find this key at the following location –


Note: The RootShareAcquireSuccessEvent field has the following possible values:

      • Default value = 1; enables the log.
      • Value other than 1; disables the log.

This key will be created automatically on your device after upgrading to OS Build 18363.1411. However, you must restart the DFSN service so that this key comes into effect. 

Other Fixes and Improvements

  • Users may update to Windows Server 2019 using a .iso image. However, if you rename the default admin account, the Local Security Authority (LSA) process might stop working.
  • Adds support for using the new Chromium-based Microsoft Edge as the assigned access single kiosk app. Furthermore, users may also customize a breakout key sequence for single app kiosks.
  • Works upon an issue wherein User Datagram Protocol (UDP) broadcast packets become larger than the maximum transmission unit (MTU). Devices that receive these packets will no longer discard them just because the checksum is not valid.
  • Resolves a bug that causes the IKEEXT service to stop working intermittently.
  • Works upon an issue that restricts the User Profile Service from detecting a slow or a fast link reliably.
  • The WinHTTP AutoProxy service now fully complies with the value set for the maximum Time To Live (TTL) on the Proxy Auto-Configuration (PAC) file. So, there won’t be any issue that prevents the cached file from updating dynamically.
  • Improves the ability of the WinHTTP Web Proxy Auto-Discovery Service to ignore invalid Web Proxy Auto-Discovery Protocol (WPAD) URLs that the Dynamic Host Configuration Protocol (DHCP) server returns.
  • Works upon an issue that causes contention for a metadata lock when using Work Folders.
  • Updates the Open Mobile Alliance (OMA) Device Management (DM) sync protocol by adding a check-in reason for requests from the client to the server. The check-in reason will allow the mobile device management (MDM) service to make better decisions about sync sessions. With this change, the OMA-DM service must negotiate a protocol version of 4.0 with the Windows OMA-DM client. 
  • Resolves an issue with failover in an environment that only has IPv6 clusters. If the failover cluster has been running for more than 24 days, attempts to do a failover might not succeed or might be delayed.

Known Issues on this Update

No new bugs appear after installing this non-security patch to your computer. 

How to Get KB4601380 Update

Since this is an optional update, it’s not mandatory to download and install this patch on your device. However, if you do want to apply this non-security update, make sure that you have already installed the latest servicing stack update i.e. KB4601395. SSUs improve the reliability of the update process so that no new bugs pop-in during the LCU installation. 

You may get the KB4601380 update from the following channels –

1. Windows Update

  • Press Win + I to launch the Settings window.
  • Select Update & Security > Windows Update.
  • Head over to the right side and click the Optional updates link.
  • Here, you might get access to the latest non-security patch i.e. KB4601380.
  • If not, come back to the Windows Update page, and hit the Check for updates button.  
  • The system will then look for any pending updates and apply them to your computer (if available any). 

2. Update Catalog

In case you don’t get this update via Windows Update, manually download the standalone package available at the Microsoft Update Catalog site.

  • Open your default web browser and type “update catalog” in the address bar.
  • After pressing Enter, click the top link to enter Microsoft’s official site.
  • Copy/paste KB4601380 on the search bar, and press Enter.
  • There should appear a list of matching results for different system architectures.
  • Pick the one that well suits your system configuration, and hit the download button.
  • When the download completes, double-click over the setup file to complete its installation.

Release Note