To allow the deserialization of the license added to App_Licenses.dll by the Microsoft IDE, you should add the SerializationFormatter flag to security permission to the Web.config file. Complete the steps in the Modifying or Editing the Config File topic to create or modify a policy file before completing the following.

Add the SerializationFormatter flag to the <IPermission class="SecurityPermission"> tag so that it appears similar to the following:

<NamedPermissionSets>

     <PermissionSet

     class="NamedPermissionSet"

     version="1"

     Name="ASP.Net">

        <IPermission

                class="SecurityPermission"

                version="1"

                Flags="Assertion, Execution, ControlThread, ControlPrincipal, RemotingConfiguration, SerializationFormatter"/>

        ...

     </PermissionSet>

</NamedPermissionSets>