Security Exception in Web.Config On Server

Question

When I am using

<trust level="Full"/>

in Web.Config it gives error:

Configuration Error

Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser Error Message: This configuration section cannot be used at this path. This happens when the site administrator has locked access to this section using from an inherited configuration file.

But When I skip trust level, it gives error

Security Exception

Description: The application attempted to perform an operation not allowed by the security policy. To grant this application the required permission please contact your system administrator or change the application's trust level in the configuration file.

Exception Details: System.Security.SecurityException: That assembly does not allow partially trusted callers.

I had also added [assembly: AllowPartiallyTrustedCallers] in AssemblyInfo.cs, but it could not help.

Any Help will be great.

My Web.Config:

   <?xml version="1.0" encoding="utf-8"?>
<!--

<configuration>
<configSections>

     <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=4.4.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
   </configSections>
  <connectionStrings>

        // Here is my connection string
    </connectionStrings>
  <appSettings>
 <add key="webpages:Version" value="2.0.0.0" />
<add key="webpages:Enabled" value="false" />
<add key="PreserveLoginUrl" value="true" />
<add key="ClientValidationEnabled" value="true" />
<add key="UnobtrusiveJavaScriptEnabled" value="true" />
 </appSettings>



   <system.web>

 <customErrors mode="Off"/>


  <compilation debug="true" targetFramework="4.0" />
  <authentication mode="Forms">
   <forms loginUrl="~/Account/Login" timeout="2880" />
  </authentication>
  <membership>
  <providers>
    <clear/>
    <add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="ApplicationServices"
         enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false"
         maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10"
         applicationName="/" />
  </providers>
</membership>

<profile>
  <providers>
    <clear/>
    <add name="AspNetSqlProfileProvider" type="System.Web.Profile.SqlProfileProvider" connectionStringName="ApplicationServices" applicationName="/" />
  </providers>
</profile>

<roleManager enabled="false">
  <providers>
    <clear/>
    <add name="AspNetSqlRoleProvider" type="System.Web.Security.SqlRoleProvider" connectionStringName="ApplicationServices" applicationName="/" />
    <add name="AspNetWindowsTokenRoleProvider" type="System.Web.Security.WindowsTokenRoleProvider" applicationName="/" />
  </providers>
  </roleManager>


   <pages>
    <namespaces>
    <add namespace="System.Web.Helpers" />
    <add namespace="System.Web.Mvc" />
    <add namespace="System.Web.Mvc.Ajax" />
    <add namespace="System.Web.Mvc.Html" />
    <add namespace="System.Web.Optimization" />
    <add namespace="System.Web.Routing" />
    <add namespace="System.Web.WebPages" />
    </namespaces>
   </pages>


  </system.web>

<system.webServer>