Windows 10 Cumulative Update updates Windows 10 to the latest build offline, so you always have the most recent installation files.

KB4346783 includes quality improvements only according to Microsoft. The update does not introduce new features or security updates.

Note: The update has one known issue that may cause Microsoft Edge to fail to load when Application Guard Window is enabled. Microsoft suggests that users remove KB4343909, install KB4340917, and re-install KB4343909 to resolve the issue.

Fixed flickering issue in Microsoft Foundation Class applications.
Addressed a reliability issue in applications with extensive window nesting.
Touch and mouse events were handled differently in Windows Presentation Foundation applications with transparent overlay windows.
Fixed several issues with Universal CRT.
Fixed client authentication issues with Edge and other UWP on TMP 2.0 devices.
Fixed "Access Denied" issue in computer certificate enrollment or renewal after installing the April 2018 update.
Fixed data decryption from memory issue after certain CAPI decryption operations complete.
Addressed a Device Guard issue that prevented PackageInspector.exe from including all files required for an application to run.
Fixed network printer connectivity issue after user sign-in.
Fixed printing on 64-bit versions of Windows when 32-bit applications "impersonate other users". The fix is to either go to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Print in the Registry and set Splwow64Compat to 1, or to use the Microsoft Application Compatibility Toolkit to enable Splwow64Compat App Compat Shim globally.
Fixed a Wi-Fi EAP-TTLS (CHAP) authentication issue.
Addressed stop code error 0xD1 DRIVER_IRQL_NOT_LESS_OR_EQUAL on devices that have 802.1x Extensible Authentication Protocol (EAP) enabled.
Addresses an issue that may remove a Dynamic Host Configuration Protocol (DHCP) option from a reservation after changing the DHCP scope settings.
Key Management Service (KMS) extended to support the upcoming Windows 10 Enterprise LTSC and Windows Server editions. Further information see KB4347075.