Web site does not show ( Says its down) , no user code is called

The site loads app_offline.htm.

The application used to load fine, im not sure whats wrong and im looking for a pointer. Its failing to load on the application. This hosted on the development asp.net server

To get this call stack i have to enable A first chance exception in System.Web.HttpExecption, here is the "console" output

A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll

A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll

Additional information: ASP.NET Initialization Error:

A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll

Additional information: ASP.NET Initialization Error:开发者_运维技巧

The call stack for the first execption.

System.Web.dll!System.Web.HttpRuntime.CheckApplicationEnabled() Line 1269C#

System.Web.dll!System.Web.HttpRuntime.FirstRequestInit(System.Web.HttpContext context = {System.Web.HttpContext}) Line 579C#

System.Web.dll!System.Web.HttpRuntime.EnsureFirstRequestInit(System.Web.HttpContext context) Line 652C#

System.Web.dll!System.Web.HttpRuntime.ProcessRequestInternal(System.Web.HttpWorkerRequest wr = {Microsoft.VisualStudio.WebHost.Request}) Line 1582 + 0x9 bytesC#

System.Web.dll!System.Web.HttpRuntime.ProcessRequestNoDemand(System.Web.HttpWorkerRequest wr) Line 2270C#

System.Web.dll!System.Web.HttpRuntime.ProcessRequest(System.Web.HttpWorkerRequest wr) Line 2256C#

The presence of 'app_offline.htm" in the root folder will prevent the app from running. Rename the file and it should allow your app to load.

Is it set up as an "application" in IIS? With the correct .NET version and all that?