Error on type WebActivatorEx.ActivationManager threw an exception …Parameter count mismatch

问题

I am getting this error after I installed Microsoft.Owin.*. Target .Net Framework:4.5.2. Web Activator: 2.2.0 I have the same setup in another project and that seems to work fine. Please help me debug or fix this.

Have I have done so far:-

Updated all Nuget Packages
Deleted obj folder contents
Ran aspnet_compiler.exe -p C:\source\Application\MyAPI -v anything -errorstack . It did give the same error, but stopped after I added WebMatrix.data.

Full Error Details :-

Parameter count mismatch. 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.

Stack Trace: 
[TargetParameterCountException: Parameter count mismatch.]
System.Reflection.RuntimeMethodInfo.InvokeArgumentsCheck(Object obj, 
BindingFlags invokeAttr, Binder binder,    Object[] parameters, CultureInfo 
culture) +11403690
System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags 
invokeAttr, Binder binder, Object[]    parameters, CultureInfo culture) +54
WebActivatorEx.BaseActivationMethodAttribute.InvokeMethod() +73
WebActivatorEx.ActivationManager.RunActivationMethods(Boolean designerMode) 
+637
WebActivatorEx.ActivationManager.Run() +103

[InvalidOperationException: The pre-application start initialization method 
Run on type    WebActivatorEx.ActivationManager threw an exception with the 
following error message: Parameter count    mismatch..]

Here's the package.config :-

  <package id="EntityFramework" version="6.1.3" targetFramework="net452" />
  <package id="log4net" version="2.0.8" targetFramework="net452" />
  <package id="Microsoft.AspNet.Razor" version="3.2.3" targetFramework="net452" />
  <package id="Microsoft.AspNet.WebApi" version="5.2.3" targetFramework="net452" />
  <package id="Microsoft.AspNet.WebApi.Client" version="5.2.3" targetFramework="net452" />
  <package id="Microsoft.AspNet.WebApi.Core" version="5.2.3" targetFramework="net452" />
  <package id="Microsoft.AspNet.WebApi.Owin" version="5.2.3" targetFramework="net452" />
  <package id="Microsoft.AspNet.WebApi.WebHost" version="5.2.3" targetFramework="net452" />
  <package id="Microsoft.AspNet.WebHelpers" version="3.2.3" targetFramework="net452" />
  <package id="Microsoft.AspNet.WebPages" version="3.2.3" targetFramework="net452" />
  <package id="Microsoft.AspNet.WebPages.Data" version="3.2.3" targetFramework="net452" />
  <package id="Microsoft.AspNet.WebPages.WebData" version="3.2.3" targetFramework="net452" />
  <package id="Microsoft.Owin" version="3.1.0" targetFramework="net452" />
  <package id="Microsoft.Owin.Host.SystemWeb" version="3.1.0" targetFramework="net452" />
  <package id="Microsoft.Owin.Security" version="3.1.0" targetFramework="net452" />
  <package id="Microsoft.Owin.Security.OAuth" version="3.1.0" targetFramework="net452" />
  <package id="Microsoft.Web.Infrastructure" version="1.0.0.0" targetFramework="net452" />
  <package id="Newtonsoft.Json" version="10.0.2" targetFramework="net452" />
  <package id="Owin" version="1.0" targetFramework="net452" />
  <package id="Swashbuckle" version="5.5.3" targetFramework="net452" />
  <package id="Swashbuckle.Core" version="5.5.3" targetFramework="net452" />
  <package id="WebActivatorEx" version="2.0" targetFramework="net452" />

回答1:

I found the issue. there was another PreApplicationStartMethod in swagger that was causing the issue. After I removed that line things started working.

来源：https://stackoverflow.com/questions/44551694/error-on-type-webactivatorex-activationmanager-threw-an-exception-parameter

标签

ASP.NET

asp.net-web-api

owin

webactivator