reflectiontypeloadexception unable to load one or more of the requested types

Hello,

I have a dialog which loads all classes that belongs to given Interface in the current Assembly , that works very nice without any error on my maschine but does not work on my collegues maschine , it gives him following error 

 void ClassSelectionDialog_Loaded(object sender, RoutedEventArgs e)
        {
            fullpath = System.IO.Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);

            foreach (string dll in Directory.GetFiles(fullpath, "*.dll"))
            {
                try
                {
                    ProxyDomain pd=new ProxyDomain();
                    Assembly asm = pd.GetAssembly(dll);
                    int cnt = asm.GetTypes().Where(p => p.GetInterface(Interface) != null).Count();
                    if (cnt > 0)
                    {
                        lstAssemblies.Items.Add(Assembly.LoadFile(dll).GetName().Name);
                        break;
                    }
                }
                catch { }
            }
            //foreach (Assembly asm in AppDomain.CurrentDomain.GetAssemblies())
            //{
            //    lstAssemblies.Items.Add(asm.GetName().Name);
            //}
        }
 class ProxyDomain : MarshalByRefObject
    {
        public Assembly GetAssembly(string AssemblyPath)
        {
            try
            {
                return Assembly.LoadFrom(AssemblyPath);
            }
            catch (Exception ex)
            {
                throw new InvalidOperationException(ex.Message);
            }
        }
    }

above is my code for loading assembly and classes. 

Sincerely, dhampall Please remember to mark the replies as answers if they help and unmark them if they provide no help.