.NET Framework June 2019 Preview of Quality Rollup

Brett Lopez

Today, we are releasing the June 2019 Preview of Quality Rollup.

Quality and Reliability

This release contains the following quality and reliability improvements.


  • Addresses an issue in which applications that target .NET Framework 4.7 and later, or that set Switch.System.Windows.Controls.Grid.StarDefinitionsCanExceedAvailableSpace to “false,” experienced hangs because of the manner in which the algorithm allocated space to grid columns or rows whose width or height include an asterisk (*). [806901]
  • Improves the memory allocation and cleanup scheduling behavior of the weak-event pattern. To opt-in to these improvements, set AppContext switches to “true”: Switch.MS.Internal.EnableWeakEventMemoryImprovements and Switch.MS.Internal.EnableCleanupSchedulingImprovements. [763101]
  • Addresses an InvalidOperationException that can arise during weak-event cleanup, if called re-entrantly while a weak-event delivery is in progress. [812614, 822169]



  • Addresses InvalidOperationException errors in System.Web.Hosting.RecycleLimitMonitor+RecycleLimitMonitorSingleton.AlertProxyMonitors. Worker processes for ASP.Net 4.7 and later are vulnerable to unexpected crashes because of this exception if the worker process consumes close to its configured Private Bytes recycling limit and application domains are being created or recycled (perhaps because of configuration file changes, or the presence of more than one application per worker process). [776516, 856170]



  • Addresses an issue in which it was possible for a Workflow Service to get into a looping situation if an unhandled exception occurs during Cancel processing. To break this cycle, the Web.config file for the workflow service can have the following AppSetting specified that will cause the workflow service instance to terminate, instead of abort, if an unhandled exception occurs during Cancel processing. [721251, 866801


<add key=”microsoft:WorkflowServices:TerminateOnUnhandledExceptionDuringCancel” value=”true”/>



1 Windows Presentation Foundation (WPF)


Getting the Update

The Preview of Quality Rollup is available via Windows Update, Windows Server Update Services, and Microsoft Update Catalog.

Microsoft Update Catalog

You can get the update via the Microsoft Update Catalog. For Windows 10, NET Framework 4.8 updates are available via Windows Update, Windows Server Update Services, Microsoft Update Catalog.  Updates for other versions of .NET Framework are part of the Windows 10 Monthly Cumulative Update.

The following table is for Windows 10 and Windows Server 2016+ versions.

Product VersionCumulative Update
Windows 10 1809 (October 2018 Update)Windows Server 20194503864
.NET Framework 3.5, 4.7.2Catalog4502559
.NET Framework 3.5, 4.8Catalog4502564
Windows 10 1803 (April 2018 Update)4502563
.NET Framework 3.5, 4.7.2Catalog4503288
.NET Framework 4.8Catalog4502563
Windows 10 1709 (Fall Creators Update)4502562
.NET Framework 3.5, 4.7.1, 4.7.2Catalog4503281
.NET Framework 4.8Catalog4502562
Windows 10 1703 (Creators Update)4502561
.NET Framework 3.5, 4.7, 4.7.1, 4.7.2Catalog4503289
.NET Framework 4.8Catalog4502561
Windows 10 1607 (Anniversary Update)Windows Server 20164502560
.NET Framework 3.5, 4.6.2, 4.7, 4.7.1, 4.7.2Catalog4503294
.NET Framework 4.8Catalog4502560


The following table is for earlier Windows and Windows Server versions.

Product VersionPreview of Quality Rollup
Windows 8.1Windows RT 8.1Windows Server 2012 R2Catalog4503867
.NET Framework 3.5Catalog4495608
.NET Framework 4.5.2Catalog4495592
.NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2Catalog4502557
.NET Framework 4.8Catalog4502567
Windows Server 2012Catalog4503866
.NET Framework 3.5Catalog4495602
.NET Framework 4.5.2Catalog4495594
.NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2Catalog4502556
.NET Framework 4.8Catalog4502566
Windows 7 SP1Windows Server 2008 R2 SP1Catalog4503865
.NET Framework 3.5.1Catalog4495606
.NET Framework 4.5.2Catalog4495596
.NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2Catalog4502558
.NET Framework 4.8Catalog4502568
Windows Server 2008Catalog4503868
.NET Framework 2.0, 3.0Catalog4495604
.NET Framework 4.5.2Catalog4495596
.NET Framework 4.6Catalog4502558


Previous Monthly Rollups

The last few .NET Framework Monthly updates are listed below for your convenience: