Server Application Unavailable

Problem

You see the following error when browsing your application:

The web application you are attempting to access on this web server is currently unavailable. Please hit the "Refresh" button in your web browser to retry your request.

Solution

This can happen for several reasons. An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Open the Event Viewer and see the error message reported. Please review this log entry to discover what caused this error.

If the error message reported is:

Aspnet_wp.exe could not be launched because the username and/or password supplied in the processModel section of the config file are invalid.

Then the most likely causes are:

Microsoft .NET Framework is no longer registered correctly.
The Microsoft Internet Information Server memory is corrupted.
The ASP.NET user no longer has access to the Microsoft .NET Framework folder, the application folder, or the Temporary Files folder.
You have recently applied a security patch to IIS.
Your system is a domain controller.
(Advanced) The processModel section of the Machine.config file does not specify AutoGenerate for the password.

If you continue to have problems, please see the Additional Resources section below.

Microsoft .NET Framework Registration issues

For #1, please:

See .NET Framework 1.1 Should be Re-Registered for instructions on how to register the .NET Framework with the Microsoft IIS web server.

Microsoft Internet Information Server memory issues

For #2, either reboot your machine or restart the Microsoft Internet Information Server (IIS) from the Command Prompt. To restart Microsoft IIS:

Step 1: Open the Command Prompt from the Start menu of your computer and go to the Programs, Accessories menu and select Command Prompt.

Step 2: Enter the following commands successively.

net stop iisadmin /y & net stop aspnet_state

net start w3svc & net start smtpsvc & net start aspnet_state

ASP.NET user issues

For #3, see ASP.NET User Does Not Have Permissions to Your Application Folder for instructions on how to grant the ASP.NET user access permissions to your application.

Security Patch issues

For #4, if you have recently applied a security patch, see these resources:

http://support.microsoft.com/?id=827641

http://www.asp.net/faq/ms03-32-issue.aspx

Domain controller issues

For #5 see:

http://support.microsoft.com/kb/315158

processModel issues

These issues are very rare, but may happen if you have modified the processModel file used by Microsoft .NET Framework. If you continue to have problems after you have tried all previous options and looked at the Additional Resources section below, then edit the Machine.config file in Notepad from the following folder:

C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322\CONFIG.

Search for processModel and within the processModel XML line, search for username and Password. The username must be “machine” and the password must be “AutoGenerate”.

IMPORTANT: We strongly advise that you save a copy of the Machine.config before you modify it. Inadvertent changes to this file may cause other problems.

Additional Resources

http://support.microsoft.com/kb/811320

http://support.microsoft.com/kb/821157

http://support.microsoft.com/kb/827641

http://support.microsoft.com/kb/834053

http://support.microsoft.com/kb/833444

http://support.microsoft.com/kb/323292