Microsoft has released a Windows 10 update that fixes multiple bugs in Windows 10, version 1909 and Windows 10, version 1903, including issue causing Windows Update to stop responding and the lock screen to stop appearing.

The optional non-security KB4550945 update was published as part of the optional monthly “C” release and it only comes with Windows 10 quality improvements.

More information on the different types of monthly quality updates released by Microsoft each month is available in the Windows 10 update servicing cadence primer.

Additional info on optional updates starting May 2020 can be found in a Windows message center announcement regarding the timing for upcoming Windows optional C and D releases.

KB4550945 will be automatically installed when checking for updates using Windows Update and you can also manually install it from the Microsoft Update Catalog.

KB4550945 highlights

Updates an issue that prevents certain apps from opening after you upgrade from a previous version of Windows, and a Bad Image error message appears.

Updates in an issue that turns off notifications for devices that use a virtual private network (VPN) on a cellular network.

Updates an issue that prevents you from resuming a Microsoft Xbox game on a Windows device after upgrading from a previous version of Windows.

Updates an issue that causes a text box that contains multiple lines of text to stop responding in certain scenarios.

Updates an issue that generates unexpected notifications when you change the default application settings.

Updates an issue that causes Windows Update to stop responding when you check for updates.

Updates an issue that fails to print content that is outside of the margins of a document.

Full list of changes in KB4550945

Addresses an issue that prevents certain apps from opening after you upgrade from a previous version of Windows, and a Bad Image exception dialog box appears.

Addresses in an issue that turns off notifications for devices that use a virtual private network (VPN) on a cellular network.

Addresses an issue that prevents you from resuming a Microsoft Xbox game on a Windows device after upgrading from a previous version of Windows.

Addresses an issue that causes a box that contains multiple lines of text to stop responding in certain scenarios.

Addresses an issue that prevents the touch keyboard from appearing during sign in when the user is prompted for the password.

Addresses an issue that prevents the touch keyboard from opening in Universal Windows Platform (UWP) apps when USB devices are connected.

Addresses an issue that displays incorrect folder properties in File Explorer when the path is longer than MAX_PATH.

Addresses an issue that prevents the correct lock screen from appearing when all of the following are true: The Group Policy Object (GPO) policy "Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options\Interactive Logon: Do not require Ctrl+Alt+Del Computer" is disabled. The GPO policy “Computer Configuration\Administrative Templates\System\Logon\Turn off app notifications on the lock screen” is enabled. The registry key HKLM\SOFTWARE\Policies\Microsoft\Windows\System\DisableLogonBackgroundImage is set to 1.

Addresses an issue that generates unexpected notifications related to changing the default application settings.