FIX: Some Antivirus Programs May Cause Web Applications to Restart Unexpectedly

Some antivirus programs may cause Web applications to restart unexpectedly. If your computer is experiencing this problem, you may notice the following:

• The Web applications or Application Domains (AppDomains) restart, although you have not changed any critical files. Critical files include the Web.config file, the Global.asax file, or any files in the Bin folder. (Each Web application is assigned to a single AppDomain.)
• The AppDomain restarts cause the value of the ASP.NET Application Restarts Performance Monitor counter to increase.
• The AppDomain restarts cause sessions to restart if you are using the InProc session state mode.
• The AppDomain restarts may cause slow performance.

Some antivirus programs change the archive bit of a file. Others change the creation date or the time that the file was last written to. If any of these changes occur on one of the critical files or folders, ASP.NET detects the change, and then restarts the AppDomain.

A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next .NET Framework 1.0 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site: Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The English version of this fix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

This hotfix has been tested for use with antivirus programs from the following third-party companies:

• ETrust
• McAfee
• Symantec\Norton

Note Symantec has a fix available for on-demand scanning. This fix enables on-demand scanning to run without causing an AppDomain restart. Real-time scanning does not cause this problem.