Error message when an ASP.NET application tries to create a new application domain: "Can not access file 'System.Web' because it is being used by another process" (919079)



The information in this article applies to:

  • Microsoft ASP.NET (included with the .NET Framework) 1.0
  • Microsoft ASP.NET (included with the .NET Framework 1.1)
  • Microsoft ASP.NET 2.0

SYMPTOMS

Consider the following scenario. You create a Microsoft ASP.NET application. The application tries to create a new application domain. In this scenario, you may receive the following configuration error message in the Web browser:
Configuration Error

Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser Error Message: Can not access file 'System.Web' because it is being used by another process.
Notes
  • In this error message, the words "can not" are a misspelling for the word "cannot."
  • This problem is more likely to occur when the Web server is under a heavy load.

CAUSE

This problem occurs when a process modifies the Machine.config file at the same time that the System.web.dll file tries to access the Machine.config file. This causes a file sharing violation.

Note The error message that is mentioned in the "Symptoms" section indicates that the System.web.dll file cannot be accessed. However, the problem is that the Machine.config file cannot be accessed by the System.web.dll file.

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

Modification Type:MajorLast Reviewed:7/6/2006
Keywords:kbtshoot kbprb KB919079 kbAudDeveloper