Ho provato ad aggiungere anche la stringa relativa al Framework ma nulla da fare la pagina in ASPX non me la carica; non è che ci sarà qualche errore nella pagina ?

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


<configuration>
  
  <appSettings>
    <add key="ConnectionString"
    value="***********************++;"/>
    <add key="MaximumRequests" value="2" />
  </appSettings>


  <system.web>
    
      <compilation debug="true" targetFramework="4.5" />
      <httpRuntime targetFramework="4.5" />
  
    <customErrors mode="RemoteOnly" defaultRedirect="mycustompage.htm"/>


    <trace enabled="false" requestLimit="10" pageOutput="false" traceMode="SortByTime" localOnly="true" />


    <sessionState timeout="10"
       mode="SQLServer"
       sqlConnectionString="Data Source=************************"
       cookieless="false"
    />


    <globalization culture="IT-it"
     uiCulture="IT-it"
     requestEncoding="latin9"
     responseEncoding="latin9"
    />
    
    
    </system.web>


</configuration>