无法在IIS 7.5中的WCF服务应用程序中添加程序集引用

Question

我一直在尝试在我的wcf应用程序中添加对名为CAPI_PInvoke.dll（64位）的程序集的引用。 dll放在我的bin文件夹中但当我通过https://localhost:port访问我的服务时它会出现以下错误

IIS有权读取/执行整个项目directroy的内容。
这是我的web.config文件

<?xml version="1.0"?>
<configuration>
     <startup  useLegacyV2RuntimeActivationPolicy="true">
       <supportedRuntime version="v4.0"/>
  </startup>
  <appSettings>
    <add key="aspnet:UseTaskFriendlySynchronizationContext" value="true"/>
  </appSettings>
  <system.web>
    <compilation targetFramework="4.5"/>
    <httpRuntime targetFramework="4.5"/>
  </system.web>
  <system.serviceModel>
    <bindings>
      <basicHttpBinding>
        <binding 

      maxReceivedMessageSize="2147483647" 
     >
          <readerQuotas/>
        </binding>
      </basicHttpBinding>
    </bindings>
    <behaviors>
      <serviceBehaviors>
        <behavior>
          <!-- To avoid disclosing metadata information, set the values below to false before deployment -->
          <serviceMetadata httpGetEnabled="true" httpsGetEnabled="true"/>
          <!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid disclosing exception information -->
          <serviceDebug includeExceptionDetailInFaults="true"/>
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <protocolMapping>
      <add binding="basicHttpsBinding" scheme="https"/>
    </protocolMapping>
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true"/>
  </system.serviceModel>
  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true"/>
    <!--
        To browse web app root directory during debugging, set the value below to true.
        Set to false before deployment to avoid disclosing web app folder information.
      -->
    <directoryBrowse enabled="true"/>
  </system.webServer>
</configuration>

我已经研究了几篇文章但无法解决问题，有人能建议解决这个问题吗？