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A bunch of windows updates were performed on our windows 2008 server over the weekend.

Unfortunately now our site has gone down and it displaying the 500 error.

In the event viewer, the following message is being displayed:

IISWMSVC_AUTHENTICATION_UNABLE_TO_READ_CONFIG An unexpected error occurred while retrieving the authentication information. Exception:System.UnauthorizedAccessException: Filename: \?\C:\Windows\system32\inetsrv\config\redirection.config Error: Cannot read configuration file due to insufficient permissions at Microsoft.Web.Administration.Interop.AppHostAdminManager.GetAdminSection(String bstrSectionName, String bstrSectionPath) at Microsoft.Web.Administration.Configuration.GetSectionInternal(ConfigurationSection section, String sectionPath, String locationPath) at Microsoft.Web.Administration.ConfigurationManager.LoadRedirectionInfo() at Microsoft.Web.Administration.ConfigurationManager.GetAdministrationConfigMapIfNeeded() at Microsoft.Web.Administration.ConfigurationManager.SetAdminManagerProperties(WebConfigurationMap webConfigMap, Boolean isAdminConfig, IAppHostAdminManager adminManager, Boolean isRemote) at Microsoft.Web.Administration.ConfigurationManager.CreateWritableAdminManager(WebConfigurationMap webConfigMap, String configPathToEdit, Boolean isAdminConfig) at Microsoft.Web.Administration.ConfigurationManager.CreateConfiguration(WebConfigurationMap configMap, String configPathToEdit, Boolean isAdminConfig) at Microsoft.Web.Administration.ConfigurationManager.GetConfiguration(String rawConfigurationPath, String cacheKey, Boolean isAdminConfig) at Microsoft.Web.Management.Server.ConfigurationAuthenticationProvider.GetSection(ServerManager serverManager) Process:dllhost User=NT AUTHORITY\NETWORK SERVICE

It seems to be only the PHP front end pages that are affected in our site. Our site backend (everything from the login screen) are .NET MVC pages, and they are working fine.

I have tried adding permissions to the config folder for NT AUTHORITY\NETWORK SERVICE, and also the application pool for our application however none of these resolved the issue.

i'm not a sysadmin so I'm not overly familar with this kind of stuff. I'd be grateful if anyone can anyone offer some advice?

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This is just a guest because I head similar problems with an isapi handler:

How are you running php? If it is 32bit isapi extension, and your server is a 64bit win2k8 ( which is the default since Win2k8R1 I believe ), you have to assign your extension on a 32 bit pool. If your php is current assigned to a 64bits pool, 32bits application can not access C:\Windows\system32 on 64bit systems, so this would explain the error you have.

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Hi Olivier, thanks, something like that actually sounds vaguely familiar. I've checked out the isapi filters in IIS for the site, however there is no PHP isapi extension :S I added it in, however it didn't seem to make a difference. Without the isapi filter, the page seems to try to load for about 30 seconds, then displays the 500 error. With the php isapi filter, it immediately displays the 500 error. Not sure if that matters to the situation or not. – 109221793 Nov 6 '11 at 13:57
Did you check to which pool your application is attached? Is it 64bits or a 32bits pool? – Olivier S Nov 10 '11 at 6:31

The error namechecks redirection.config, which means it's trying to read the shared configuration configuration. It could be a problem specific to the data in the file, if you're using s.c. Or could be a problem reading the file, which procmon from sysinternals might be able to identify.

Other info: wmsvc is named, web management service? And dllhost is identified as the source process... No idea what that's about.

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