.NET Framework August 2018 Preview of Quality Rollup

Tara Overfield

Last Updated 9/7/2018: Documented missing WPF updates

Today, we are releasing the August 2018 Preview of Quality Rollup.

Quality and Reliability

This release contains the following quality and reliability improvements.


  • Resolves an issue where an ASP.NET web application is continuously running under high load on high-end web server(40+ CPU cores), it may suffer high thread contention which can cause high CPU usage. [624745]


  • Fixes an issue that results in a System.InvalidProgramException for some very large XSLT transforms. This may also fix this kind of issue for some other very large methods. [604943]
  • Addresses an issue where a the CultureAwareComparer type was not able to correctly serialize and deserialize across different versions of the .NET Framework, as described in Advisory serializing/deserializing a CultureAwareComparer with .NET Framework 4.6+. [637591]


  • Resolves an issue where SqlClient login may use an infinite timeout due to truncating a small millisecond timeout to zero when converting to seconds. [631196]


  • A race-condition existed in AsyncResult that closes a WaitHandle before Set() is called. When this happens, the process crashes with an ObjectDisposedException. [590542]
  • Enable customers using .NET 2.0, 3.0, 3.5, 3.5.1 to use their program under TLS 1.1 or TLS 1.2 [639940]


  • In multi-threaded WPF applications that process large packages simultaneously, there is potential for a deadlock when one of these files is closing and the other starts to consume larger amounts of memory.[602405]
  • Under certain conditions, WPF applications (like SCCM) using WindowChromeWorker experience high CPU usage or hangs. [621651]
  • In certain .NET applications, timing issues in the finalizer thread could potentially cause exceptions during AppDomain or process shutdown. This is generally seen in applications that do not correctly shut down Dispatchers running on worker threads prior to process or AppDomain shutdown. Such applications should take care to properly manage the lifetime of Dispatchers. This change adds an AppContext switch that can help alleviate (but not eliminate) some of the issues that may arise from these application design issues. To enable this, set the AppContext flag “Switch.MS.Internal.DoNotInvokeInWeakEventTableShutdownListener=true”. [609469]
  • ComboBox grouped items now report children correctly via UIAutomation. [504282]
  • Replaced multiple characters with a single character from IMEPad input now succeeds. [515186]

Note: Additional information on these improvements is not available. The VSTS bug number provided with each improvement is a unique ID that you can give Microsoft Customer Support, include in StackOverflow comments or use in web searches.

Getting the Update

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

Microsoft Update Catalog

You can get the update via the Microsoft Update Catalog. For Windows 10, .NET Framework updates are part of the Windows 10 Monthly Rollup.

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

Product Version Preview of Quality Rollup KB
Windows 10 1803 (April 2018 Update) Catalog 4346783
.NET Framework 3.5 4346783
.NET Framework 4.7.2 4346783
Windows 10 1709 (Fall Creators Update) Catalog 4343893
.NET Framework 3.5 4343893
.NET Framework 4.7.1, 4.7.2 4343893
Windows 10 1703 (Creators Update) Catalog 4343889
.NET Framework 3.5 4343889
.NET Framework 4.7, 4.7.1, 4.7.2 4343889
Windows 10 1607 (Anniversary Update) Windows Server 2016 Catalog 4343884
.NET Framework 3.5 4343884
.NET Framework 4.6.2, 4.7, 4.7.1, 4.7.2 4343884

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

Product Version Preview of Quality Rollup KB
Windows 8.1 Windows RT 8.1 Windows Server 2012 R2 Catalog 4346082
.NET Framework 3.5 4342310
.NET Framework 4.5.2 4342317
.NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.1, 4.7.2 4342315
Windows Server 2012 Catalog 4346081
.NET Framework 3.5 4342307
.NET Framework 4.5.2 4342318
.NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.1, 4.7.2 4342314
Windows 7 Windows Server 2008 R2 Catalog 4346080
.NET Framework 3.5.1 4342309
.NET Framework 4.5.2 4342319
.NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.1, 4.7.2 4342316
Windows Server 2008 Catalog 4346083
.NET Framework 2.0, 3.0 4342308
.NET Framework 4.5.2 4342319
.NET Framework 4.6 4342316

Previous Monthly Rollups

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


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