Replacement System.Configuration.ConfigurationManager is incompatible

[hunkydoryrepair]

Describe the bug
Microsoft provides a .NET Standard compatible version of System.Configuration.ConfigurationManager which we have been using in .NET 10 successfully for many projects. Using the replacement from WebFormForCore creates an incompatibility where it throws an error when not recognizing standard sections, such as appSettings and connectionStrings.

(Moreover, it seems to require .NET framework libraries (webengine4.dll), so we are running into exceptions because that assembly is not available, but this is a separate bug. One that could be solved if this assembly were just not used)

To Reproduce
Steps to reproduce the behavior:

1. Attempt to read in app.config with an section
2. See error

Expected behavior
Compatibility with original ConfigurationManager that understood appSettings, connectionStrings (and probably more). OR the ability to use the official System.Configuration.ConfigurationManager

[hunkydoryrepair]

Related Problem:

Our app has a fair amount of pre-initilialzation. Something is triggering the configuration system to be loaded, even if we bypass reading of the app.config file (in fact I deleted app.config).

Unfortunately, something is triggering an error during app.Run. As best i can tell, this is being initialized the first time we access any LINQ object (literally we just add an object to a List and the app.config gets read in). But we have about a dozen .net standard libraries we load. Some of them are 3rd party a few use ConfigurationManager. System.Runtime.Caching from microsoft is one of them. Also Authorize.NET SDK.

Microsoft.AspNetCore.Hosting.Diagnostics: Critical: Application startup exception

System.InvalidOperationException: The configuration system has already been initialized.
at System.Configuration.ConfigurationManager.SetConfigurationSystem(IInternalConfigSystem configSystem, Boolean initComplete)
at System.Configuration.Internal.InternalConfigSettingsFactory.System.Configuration.Internal.IInternalConfigSettingsFactory.SetConfigurationSystem(IInternalConfigSystem configSystem, Boolean initComplete)
at System.Web.Configuration.HttpConfigurationSystem.EnsureInit(IConfigMapPath configMapPath, Boolean listenToFileChanges, Boolean initComplete)
at System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException)
at System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel)
at System.Web.Hosting.ApplicationManager.CreateAssemblyLoadContextWithHostingEnvironment(String appId, IApplicationHost appHost, HostingEnvironmentParameters hostingParameters, Boolean newLoadContext)
at System.Web.Hosting.ApplicationManager.CreateAssemblyLoadContextWithHostingEnvironmentAndReportErrors(String appId, IApplicationHost appHost, HostingEnvironmentParameters hostingParameters, Boolean newLoadContext)
at System.Web.Hosting.ApplicationManager.CreateInstanceInNewWorkerLoadContext(Type type, String appId, VirtualPath virtualPath, String physicalPath, Boolean newLoadContext)
at Microsoft.AspNetCore.Builder.WebFormsMiddleware.CreateWorkerLoadContextWithHost(String virtualPath, String physicalPath, Type hostType)
at Microsoft.AspNetCore.Builder.WebFormsMiddleware.get_Host()
at Microsoft.AspNetCore.Builder.WebFormsMiddleware..ctor(RequestDelegate next, Action1 optionsBuilder) at InvokeStub_WebFormsMiddleware..ctor(Object, Object, Object, Object, Object) at System.Reflection.ConstructorInvoker.InvokeImpl(Object arg1, Object arg2, Object arg3, Object arg4) at System.Reflection.ConstructorInvoker.Invoke(Span1 arguments)
at Microsoft.Extensions.DependencyInjection.ActivatorUtilities.ConstructorMatcher.CreateInstance(IServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ActivatorUtilities.CreateInstance(IServiceProvider provider, Type instanceType, Object[] parameters)
at Microsoft.AspNetCore.Builder.UseMiddlewareExtensions.ReflectionMiddlewareBinder.CreateMiddleware(RequestDelegate next)
at Microsoft.AspNetCore.Builder.ApplicationBuilder.Build()
at Microsoft.AspNetCore.Builder.ApplicationBuilder.Build()
at Microsoft.AspNetCore.Hosting.GenericWebHostService.StartAsync(CancellationToken cancellationToken)

[hunkydoryrepair]

Note that under webforms, this initialization we would do in Global.aspx.cs/application_start

Application_Start is not being called so I am trying to initialize it the way we do in our other asp.net core applications

[hunkydoryrepair]

I removed references to System.Runtime.Cache, which break ConfigurationManager, which gets me a little further, but consistent get an empty 200 response on the first request, and this error on every request afterwards. Still seems Configuration related, but it is fully in the useWebForms handler as I put handlers before and after.

webengine4.dll is really odd. System.Web.dll is load the assembly tagged with Estrellas de Esperanze. There is probably some other error first, that leads it to trying to load the Error handling config from the configuration files, which is what causes this error.

[DllNotFoundException: Unable to load DLL 'webengine4.dll' or one of its dependencies: The specified module could not be found. (0x8007007E)]
   System.Web.UnsafeNativeMethods.IsapiAppHostGetSiteName(String appId, StringBuilder buffer, Int32 size) +0
   System.Web.Configuration.MetabaseServerConfig.MBGetSiteNameFromSiteID(String siteID, String& siteName) +197
   System.Web.Configuration.MetabaseServerConfig..ctor() +87
   System.Web.Configuration.MetabaseServerConfig.GetInstance() +213
   System.Web.Configuration.IISMapPath.GetInstance() +81
   System.Web.Configuration.HostingPreferredMapPath.GetInstance() +51
   System.Web.Configuration.WebConfigurationHost.ChooseAndInitConfigMapPath(Boolean useConfigMapPath, IConfigMapPath configMapPath, ConfigurationFileMap fileMap) +243
   System.Web.Configuration.WebConfigurationHost.InitForConfiguration(String& locationSubPath, String& configPath, String& locationConfigPath, IInternalConfigRoot configRoot, Object[] hostInitConfigurationParams) +512
   System.Configuration.Configuration..ctor(String locationSubPath, Type typeConfigHost, Object[] hostInitConfigurationParams) +502
   System.Configuration.Internal.InternalConfigConfigurationFactory.System.Configuration.Internal.IInternalConfigConfigurationFactory.Create(Type typeConfigHost, Object[] hostInitConfigurationParams) +84
   System.Web.Configuration.WebConfigurationHost.OpenConfiguration(WebLevel webLevel, ConfigurationFileMap fileMap, VirtualPath path, String site, String locationSubPath, String server, String userName, String password, IntPtr tokenHandle) +1750
   System.Web.Configuration.WebConfigurationManager.OpenWebConfigurationImpl(WebLevel webLevel, ConfigurationFileMap fileMap, String path, String site, String locationSubPath, String server, String userName, String password, IntPtr userToken) +241
   System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration(String path) +98
   System.Web.Hosting.HostingEnvironment.get_CacheStoreProviderSettings() +184
   System.Web.Caching.Cache.GetInternalCache(Boolean createIfDoesNotExist) +259
   System.Web.Caching.Cache.get_InternalCache() +52
   System.Web.CachedPathData.GetConfigPathData(String configPath) +589
   System.Web.CachedPathData.GetVirtualPathData(VirtualPath virtualPath, Boolean permitPathsOutsideApp) +767
   System.Web.HttpContext.GetFilePathData() +109
   System.Web.HttpContext.GetConfigurationPathData() +85
   System.Web.HttpContext.GetRuntimeConfig() +52
   System.Web.Configuration.RuntimeConfig.GetConfig(HttpContext context) +102
   System.Web.Configuration.CustomErrorsSection.GetSettings(HttpContext context, Boolean canThrow) +123
   System.Web.HttpResponse.ReportRuntimeError(Exception e, Boolean canThrow, Boolean localExecute) +396
   System.Web.HttpRuntime.FinishRequest(HttpWorkerRequest wr, HttpContext context, Exception e) +634

[hunkydoryrepair]

This may be related to issue #9

Stepping through, first thing I find is the HttpRuntime.InitializeHostingFeatures is cut short due to the exception:
"The application's configuration files must contain 'trust' section."

so it successfully gets trustSection in ApplicationManager.cs here:
(TrustSection)configuration.GetSection("system.web/trust");

but in HttpRuntime.GetInitConfigSections, it tries to use the RuntimeConfig methods, which incorporates a cache, which ultimately throws an exception on AppDomain.CurrentDomain.IsDefaultAppDomain in the HostingEnvironment.CacheStoreProviderSettings getter.

From what I read, this is no longer an appropriate thing to call. it is part of .NET framework and not relevant to an asp.net CORE application which always has exactly 1 app domain, so it will always be the default. This could probably be replaced with "true"

There is also a point later where it will try to useMetaBase, calling "MetabaseServerConfig.GetInstance", which in turn calls UnsafeNativeMethods.IsapiAppHostGetSiteName and tries to load webengine4.dll. I headed this off by making useMetaBase always return false.

I can now get through the app initialization and it will attempt to process Global.asax. Unfortunately, I'm running into some other issue now (says i need a reference to System.web.dll, even after I've been stepping through that assembly, so I think my build of System.Web.DLL has the wrong guid or I need to get Global.asax.cs recompiled using the correct references)

[simonegli8]

Hi,

Thanx for reporting this issue. Unfortunately at the moment, I cannot tell yet when I'll have time to dig into this, as I'm quite busy and only work as a programmer part time, and I have some other work that needs to be done first. But thank you anyway for reporting this. As far as I remeber, WebFormsForCore uses it's own version of ConfigurationManager because it uses just the System.Configuration source files from the original .NET Framework source, and requires some stuff from there that is not in ConfigurationManager. Probably one could solve it, so it uses .NET Core's ConfigurationManager, but as far as I remember then it would not be possible to use web.config instead of app.config

[simonegli8]

If you can, I'd be glad if you could have me a GitHub Repo reproducing this issue, so I could dig into it. I don't charge for this, since it's a bug of WebFormsForCore.