Hotfix rollup 3095335 for the .NET Framework 4.5, 4.5.1, and 4.5.2 on Windows

Prerequisites

To apply this hotfix, you must have the .NET Framework 4.5.2, the .NET Framework 4.5.1, or the .NET Framework 4.5 installed.

Restart requirement

You have to restart the computer after you apply this hotfix if any affected files are being used. We recommend that you close all .NET Framework-based applications before you apply this hotfix.

Hotfix replacement information

This hotfix package doesn't replace a previously released hotfix package.

Issues that this hotfix rollup fixes

Issue 1

Assume that you use a Windows Presentation Foundation (WPF) application. A WPF TreeView can spontaneously scroll to an unpredictable position after you add a new item. This issue occurs when the following conditions are true:

• The new item is the last of its parent's children.
• The parent item is the last of its parent's children.
• The new item is visible at the current scroll position.

Issue 2

In a WPF application, removing an editing control from the visual tree can leak an ImmComposition object. Doing this repeatedly can eventually cause an out-of-memory exception.

Note An "editing control" is any control that creates and uses a TextEditor object. The main examples are TextBox, RichTextBox, and FlowDocumentScrollViewer.

Issue 3

A WPF application can become deadlocked when the following conditions are true: ​

• The application raises an event whose delivery is routed through the weak-event system.
• Another thread is concurrently using the weak-event system. This causes the first thread to wait for a lock.
• When it waits, the thread's message pump receives a message that causes re-entrancy into the application's code.
• The re-entered code tries to use the weak-event system.

This is observed most frequently with the PropertyChanged event of INotifyPropertyChanged, where the re-entered code also tries to raise a PropertyChanged event.

This is fixed in the weak-event system by waiting for locks in a way that doesn't run the thread's message pump.

Issue 4

When you try to run a command on the server, it times out on the client side, but finishes on the server. In this situation, the client sends an attention packet to the server and sets itself into a timed-out state. However, it doesn't reset it as soon as it recovers from the timed-out state after the server processed the statement that the client timed out on.

Note A byproduct of this issue will include issues with SqlDataReader reporting HasRows being true. However, calling Read from the SqlDataReader will result in no rows being read.

This hotfix resets the state of the client when it recovers from the timed-out state.

Issue 5

In some circumstances, some files in the ASP.NET shadow cache can become corrupted during computer shutdown. This may cause unpredictable behavior or exceptions being raised by applications that use the cache.

This hotfix makes sure that the cache contents are more proactively flushed to disk.

Issue 6

Computers that have 80 gigabytes (GB) or more of memory can experience decreases in performance in low memory situations because of the Garbage Collector running back to back Gen2 collections.

This hotfix includes changes to the Garbage Collector adjusting the conditions in which Gen2 collections occur on computers that have 80 GB or more of memory.

Known issues

A fix that was previously released for touch-enabled VSTO add-ins in WPF was found to have a regression in scenarios in which partial-trust applications are used on touch-enabled devices. In these scenarios, customers see an application crash and cannot load a partial trust application. Therefore, the fix for touch-enabled VSTO add-ins has been removed.