You have a web application that is deployed to a web farm environment that has two or more web servers.
The time stamp on the ASP.NET AJAX assembly (System.Web.Extensions.dll) in the Global Assembly Cache (GAC) does not match across web servers in the farm.
The partial postback is serviced by a web server other than the one that services the original request.
Note The time stamp of assemblies in the GAC is determined by the installation date and time.
In this situation, ASP.NET AJAX scripts served by the ScriptResource.axd and WebResource.axd handlers will be included more than one time on the page of the web application. Therefore, the same script may run more than one time. This may cause the web client to crash or you may experience unexpected behavior.
When the ASP.NET AJAX assembly (System.Web.Extensions.dll) in the GAC generates ScriptResource.axd and WebResource.axd links in a page, the time stamp of System.Web.Extensions.dll is used to generate the "t" parameter.
In the following example, the %t parameter% is generated based on the time stamp of the assembly System.Web.Extensions.dll.
In the scenario that is described in the "Symptoms" section, the "t" parameter will be different across the web servers in the farm.
Hotfix replacement information
The hotfix that corresponds to Microsoft Knowledge Base article 968108 (KB968108) has been superseded by hotfix KB2387928. Hotfix KB2387928 contains all the fixes that were previously included in KB968108. You should use hotfix KB2387928 to fix the issues that are described in KB968108. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
2387928 FIX: You receive the error "Operation Aborted" when you use an AJAX-based web application that is built in the .NET Framework 3.5 Service Pack 1
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.