September 2009 - this post is just her for "historical" purposes. 
For a maintained list of ASP.NET fixes click here.

[last update - 20th November 2007 - added 938276 and .NET 2.0 SP1 entry,]
[previous update - 31st August 2007 - added 939866,]
[previous update - 3rd August 2007 - corrected some of the versions for current beta products]

There is nothing worse than wrestling with a problem for ages only to discover later that there is already a fix for it. I therefore felt it would be useful to summarise what fixes have been done for ASP.NET 2.0 since it was released. Here are a few important points before we go any further:

  • What is a hotfix? Make sure you can answer this question before you go ahead and start downloading or installing fixes. A good description can be found on the DevDiv Hotifx Public Availability Pilot Program web site.
  • When we ship a fix we always try to minimise the number of files affected. So far, most ASP.NET 2.0 fixes we've released only affect three files: System.web.dll, WebEngine.dll and aspnet_wp.exe. The fixes listed in the first table below all update those files to the version number indicated.
  • Fixes are cumulative. So for example if you install the fix that says it installs version .832 then you are also getting the bug fix that is described in the article that says it installs version .819, .804 etc., etc. That's why I've written the below table in reverse version number order.
  • Check the version number of these files on your system first. If your version number is already higher than the version number indicated in the article then it means you already have that bug fix. If you are getting a problem that sounds like what is described in the article but you already have that fix, then you are probably getting a similar problem or set of symptoms due to some different underlying root cause.
  • At the time of writing, the simplest way to get all the latest, current ASP.NET 2.0 fixes is to go to Microsoft Update and let it scan your system and get all recommended critical updates. This will include MS07-040 which updates significant chunks of the Microsoft .NET Framework 2.0, including ASPNET 2.0.
  • If for some reason you don't want that security update but want a more targetted hotfix package for ASP.NET only then the next simplest thing would be to go to the connect site and directly download one of the fix packages for ASP.NET that are available there that includes the fix you are looking for (see below).
  • If you are still not sure what fix you need, are having trouble getting hold of a particular fix, are having trouble installing it or have installed it but it hasn't solved your problem then contact Microsoft Product Support.  Scott Guthrie has already blogged about one of the recent fixes listed below and has an excellent introduction to how to contact support (see "Contacting Microsoft Product Support" on that blog entry).
  • If you are having a specific problem obtaining or installing a fix or with solving some ASP.NET issue please don't contact me directly. Unfortunately I cannot scale up to be a one man support organisation. Please utilise our global support organisation as described above.

 

Fixes that affect the three core ASP.NET 2.0 files of System.Web.dll, WebEngine.dll and aspnet_wp.exe (located in \Windows\Microsoft.NET\Framework\v2.0.50727)

Version Comment Description
2.0.50727.1433   Microsoft .NET Framework 2.0 SP1 (included with .NET Framework 3.5)
2.0.50727.1378 Beta This is not a released hotfix, however Microsoft .NET Framework 3.5 Beta 2 does update the core .NET 2.0 Framework files including the ASP.NET 2.0 files and therefore includes all the below listed hotfixes. So this may be of interest if you are working with the Orcas betas.
2.0.50727.1373 Beta Windows Server 2008 June CTP
2.0.50727.1320 Beta Windows Server 2008 Beta 3
2.0.50727.1318 Beta Microsoft .NET Framework 3.5 Beta 1
2.0.50727.945   FIX: Error message when you try to run an ASP.NET 2.0 Web application if you do not associate the My_Computer_Zone code group with the "full trust" permission set: "Server Application Unavailable"
2.0.50727.926   FIX: Error message when you run an ASP.NET 2.0 Web application that is built on the .NET Framework 2.0: "The constructor to deserialize an object of type '<custom object>' was not found"
2.0.50727.924   FIX: Error message when you run an ASP.NET 2.0 Web application that is built on the .NET Framework 2.0 after you install the MS07-040 security update: "Type 'System.Web.HttpHeaderCollection' is not marked as serializable"
2.0.50727.924   FIX: The # Induced GC performance counter value increases quickly and CPU usage becomes high when you run an ASP.NET 2.0 Web application that is built on the .NET Framework 2.0
2.0.50727.912   FIX: A RemotingException exception occurs when you compile a large Web site project that is built on the .NET Framework 2.0 by using the ASP.NET Compilation tool
2.0.50727.900   FIX: Blocking problems may occur when you use SQL Server to store ASP.NET session state information for a Web site that experiences high loads
2.0.50727.832   MS07-040: Vulnerabilities in the .NET Framework could allow remote code execution

Although this security update patches the core ASP.NET 2.0 files and therefore includes all the below fixes, it also patches many other files in the .NET 2.0 Framework. Please read the above article before proceeding.
2.0.50727.819 ScottGu blog

Download on Connect
FIX: You may receive an exception when you browse a .NET Framework 2.0 ASP.NET Web application
2.0.50727.819 I wrote this article :-) FIX: Error message if you modify a resource file when an ASP.NET 2.0 application is running: "System.InvalidOperationException The resource class for this page was not found"
2.0.50727.804   FIX: Error message when you try to visit an ASP.NET 2.0-based Web page: "HttpException (0x80004005): '/HandlerTest/WebForm1.aspx/a:b' is not a valid virtual path"
2.0.50727.802   FIX: A Web application that is built by using ASP.NET 2.0 does not use the attribute value that you set in the xhtmlConformance element
2.0.50727.312   Windows Vista RTM Release includes this version
2.0.50727.244   FIX: An InvalidViewState exception is not thrown as expected when you use the Triple DES encryption type to validate the System.Web.UI.Control.ViewState property in the .NET Framework 2.0
2.0.50727.219   FIX: You may receive an "InvalidCastException" error message when you try to debug the dump files for Windows SharePoint Services
2.0.50727.213   FIX: The data in a POST request is truncated to 49,152 bytes when an ASP.NET-connected application receives the POST request
2.0.50727.210 Contained in MS06-056

I wrote this article :-)
FIX: Some characters in a text resource may not appear correctly when you try to embed the text resource in a Web application that is built on the .NET Framework 2.0
2.0.50727.174   FIX: Error message when you try to run an ASP.NET 2.0 Web application that includes Web services: "The file <FilePath> does not exist"
2.0.50727.166   FIX: You may experience an unexpected AppDomain restart in an ASP.NET Web application that is based on the .NET Framework 2.0
2.0.50727.103   FIX: The Click event for the associated Button control is not raised when page validation fails in a Web application that was built by using ASP.NET 2.0
2.0.50727.103  

FIX: You receive a ThreadAbortException exception in an ASP.NET Web application that is based in the .NET Framework 2.0 when the Async page directive property is set to true

2.0.50727.80 Download on Connect

FIX: You may receive an InvalidCastException error in an ASP.NET-connected Web application

2.0.50727.62 Download on Connect FIX: You receive an exception error message when you specify a Content-Length HTTP header that is larger than 2 GB in ASP.NET 2.0
2.0.50727.62   FIX: Error message when you try to run a Web application that was built by using the .NET Framework 2.0: "Overwhelming changes have occurred"
2.0.50727.62   FIX: Error message when you try to go to an ASP.NET page by using a URL that contains Unicode characters: "HTTP error 400 'bad request'"
2.0.50727.62   FIX: ASP.NET 2.0-connected applications on a Web site may appear to stop responding
2.0.50727.56   FIX: Error message when you try to browse the root folder of a Web application that is built on the .NET Framework 2.0: "Object reference not set to an instance of an object"

 

Other fixes outside of the main set of three files:

2.0.50727.803 System.Web.Mobile.dll FIX: You may experience a decrease in the performance of a .NET Framework 2.0-based application when you call the System.Web.UI.MobileControls.Style.GetValue method many times
2.0.50727.92 AspNetMMCExt.dll FIX: IntelliSense does not work when you use the MMC Snap-In for ASP.NET or the Web Site Administration Tool to add an existing Web.config file to a .NET Framework 2.0 ASP.NET Web site

 

Hope this helps!

Doug