.net System.Security.SecurityException:请求“System.Security.Permissions.ReflectionPermission”类型的权限失败

我已经将我的web.config文件设置为完全信任，那么为什么我仍然收到此错误

该站点在Mono.NET和内置的.NET Web服务器下运行良好，但在IIS 7下运行不好

<system.web>
    <!-- trust level-->
    <securityPolicy>
      <trustLevel name="Full" policyFile="internal" />
      <trustLevel name="High" policyFile="web_hightrust.config" />
      <trustLevel name="Medium" policyFile="web_mediumtrust.config" />
      <trustLevel name="Low" policyFile="web_lowtrust.config" />
      <trustLevel name="Minimal" policyFile="web_minimaltrust.config"/>
    </securityPolicy>
    <trust
       level="Full"
       originUrl=""
       processRequestInApplicationTrust="true"
   />

   ...
   </system.web>