DotNetNuke 4.0.0 - Issues with Medium Trust

This is another issue that crops up regularly on the ASP.NET Forums, so I have decided to create a Blog that I can refer people to.

DotNetNuke 4.0.0 has a number of issues with Medium Trust, due to undocumented changes in how .NET 2 handles partial trust situations.

1. The first is one of the attributes on the node in web.config, which does not support the compilerOptions attribute under Medium Trust.  Luckily this does not appear to be a problem as removing it apparently causes no other problems.
   
2. The second is that the provider sections of the web.config (ie the sections under cannot be parsed under Medium Trust.  This is a new, undocumented change, as the code to parse this worked fine under Medium Trust with .NET 1.1. 
   The solution is to add the attribute requirePermission="false"  to all the provider declaration sections.
      
        
   requirePermission="false" type="DotNetNuke.Framework.Providers.ProviderConfigurationHandler, DotNetNuke" />.
   I only found out the solution to this by carefully reading the error message when the attribute is missing - the default.  As a final irony, adding this attribute causes Intellisense to display a warning that the name "requirePermission" is not declared.
3. The third change in behaviour that appears to cause problems under Medium Trust is in the behaviour of the XmlSerializer class.  This class gave no partial trust issues in .NET 1.1, but in .NET 2 the constructor we use in DBLoggingProvider:
               xser = New XmlSerializer(obj.GetType, l)
   wher l is an Array of Types that might appear as properties of the main type defined by obj.GetType, throws a trust error.
   This can be replaced by the simpler constructor:
               xser = New XmlSerializer(obj.GetType)
   However, if we do that then we also need to decorate the class defined by obj.GetType, with an Xml attribute that tells the Serializer that this object also contains other classes.
       _
       Public Class LogProperties

I will update this Blog as I find more issue.