I get a call this morning "the website is down": All HTTP requests are erroring, and even the custom error page is not showing. I check the Event Log:

Event Type: Warning
Event Source: ASP.NET 2.0.50727.0
Event Category: Web Event
Event ID: 1310
Date:  5/3/2013
Time:  9:22:18 AM
User:  N/A
Computer: WEB1
Description:
Event code: 3008
Event message: A configuration error has occurred.
Event time: 5/3/2013 9:22:18 AM
Event time (UTC): 5/3/2013 4:22:18 PM
Event ID: eef7cb27b0d94e81b6b533120ba57300
Event sequence: 28346
Event occurrence: 28345
Event detail code: 0
 
Application information:
    Application domain: /LM/W3SVC/109769922/Root-1-130120701639940000
    Trust level: Full
    Application Virtual Path: /
    Application Path: C:\Inetpub\wwwroot\<removed>\
    Machine name: WEB1
 
Process information:
    Process ID: 5772
    Process name: w3wp.exe
    Account name: WEB1\UCPR
 
Exception information:
    Exception type: ConfigurationErrorsException
    Exception message: Invalid access to memory location. (Exception from HRESULT: 0x800703E6) (C:\Inetpub\wwwroot\<removed>\web.config line 92) (C:\Inetpub\<removed>\capradio\web.config line 92)
 
Request information:
    Request URL: http://<removed>.error.html?aspxerrorpath=/stream/kxjz40s.m3u
    Request path: /error.html
    User host address: 70.211.65.166
    User: 
    Is authenticated: False
    Authentication Type: 
    Thread account name: WEB1\UCPR
 
Thread information:
    Thread ID: 8
    Thread account name: WEB1\UCPR
    Is impersonating: False
    Stack trace:    at System.Web.Configuration.HttpModuleAction.get_Entry()
   at System.Web.Configuration.HttpModulesSection.CreateModules()
   at System.Web.HttpApplication.InitModules()
   at System.Web.HttpApplication.InitInternal(HttpContext context, HttpApplicationState state, MethodInfo[] handlers)
   at System.Web.HttpApplicationFactory.GetNormalApplicationInstance(HttpContext context)
   at System.Web.HttpApplicationFactory.GetApplicationInstance(HttpContext context)
   at System.Web.HttpRuntime.ProcessRequestInternal(HttpWorkerRequest wr)
 
 
Custom event details:

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......

No one has touched the web config.

The error happened after a scheduled app pool recycle.

I recycle the application pool manually, and the problem vanishes.

I have no idea what has caused this and why it is resolved by recycling the app pool.

I don't expect any responses to this post, but thought I'd throw it up here anyways, just in case.