Could not load file or assembly 'Elmah' or one of its dependencies. The system cannot find the file specified

Question

I get this error after installing Asp.NET Core Module to my Windows Server (2012 R2) machine, even though I didn't use Elmah module in my project . I am publishing my Asp.NET Core 2.2 WebAPI over IIS (v8.5) by Visual Studio 2017. After getting the error, I installed elmah.corelibrary v1.2.2 (also tried with Elmah.Contrib.WebApi , Elmah.MVC ) and published again but it didn't help.

Couldn't figure out by looking to the stack trace that where is the source of exception. In any case, I attached the whole exception details:

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Server Error in '/harmony-webapi' Application.

Could not load file or assembly 'Elmah' or one of its dependencies. The system cannot find the file specified.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.IO.FileNotFoundException: Could not load file or assembly 'Elmah' or one of its dependencies. The system cannot find the file specified.

Source Error: 

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Assembly Load Trace: The following information can be helpful to determine why the assembly 'Elmah' could not be loaded.


    WRN: Assembly binding logging is turned OFF.
    To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
    Note: There is some performance penalty associated with assembly bind failure logging.
    To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].

Stack Trace: 


[FileNotFoundException: Could not load file or assembly 'Elmah' or one of its dependencies. The system cannot find the file specified.]
   System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMarkHandle stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName, ObjectHandleOnStack type) +0
   System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName) +95
   System.Type.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase) +64
   System.Web.Compilation.BuildManager.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase) +59
   System.Web.Configuration.ConfigUtil.GetType(String typeName, String propertyName, ConfigurationElement configElement, XmlNode node, Boolean checkAptcaBit, Boolean ignoreCase) +49

[ConfigurationErrorsException: Could not load file or assembly 'Elmah' or one of its dependencies. The system cannot find the file specified.]
   System.Web.Configuration.ConfigUtil.GetType(String typeName, String propertyName, ConfigurationElement configElement, XmlNode node, Boolean checkAptcaBit, Boolean ignoreCase) +550
   System.Web.Configuration.ConfigUtil.GetType(String typeName, String propertyName, ConfigurationElement configElement, Boolean checkAptcaBit) +30
   System.Web.Configuration.Common.ModulesEntry.SecureGetType(String typeName, String propertyName, ConfigurationElement configElement) +57
   System.Web.Configuration.Common.ModulesEntry..ctor(String name, String typeName, String propertyName, ConfigurationElement configElement) +57
   System.Web.HttpApplication.BuildIntegratedModuleCollection(List`1 moduleList) +173
   System.Web.HttpApplication.GetModuleCollection(IntPtr appContext) +1069
   System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers) +130
   System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context) +165
   System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context) +267
   System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext) +341

[HttpException (0x80004005): Could not load file or assembly 'Elmah' or one of its dependencies. The system cannot find the file specified.]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +523
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +107
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +688

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.7.3282.0

Answer 1

ELMAH doesn't work with ASP.NET Core. You are probably looking or ElmahCore for self-hosted logs or elmah.io for cloud-logging.

Answer 2

Alright, resolved. The problem was when I try to publish my WebAPI under "Default Web Site" or any other root web site on IIS, it throws Elmah exception because Elmah module was configured in the existing root web sites before. I tried to publish my app separately by creating a new web site on IIS and the exception is gone.