FastMember GetMembers() throw not supported exception

I am writing a generic mapper that will map properties with the same type and name among two different object. To do so i used FastMember as in the code below :

    public static void Map ( this object target, object source, bool ignoreCase = false )
    {
        if (source == null)
            throw new ArgumentNullException("source");

        if (target == null)
            throw new ArgumentNullException("target");

        var sourceType = source.GetType();
        var targetType = target.GetType();
        var sourceAcc = TypeAccessor.Create(sourceType);
        var targetAcc = TypeAccessor.Create(targetType);

        var sourceMembers = sourceAcc.GetMembers();
        var targetMembers = targetAcc.GetMembers();

        foreach ( var targetMember in targetMembers )
        {
            if (targetMember.CanWrite == false)
                continue;

            var sourceMember = sourceMembers.FirstOrDefault ( member => ((ignoreCase) ? member.Name.ToUpper() == targetMember.Name.ToUpper() : member.Name == targetMember.Name) && 
                                                                        member.Type == targetMember.Type );

            targetAcc[target, targetMember.Name] = sourceAcc[source, sourceMember.Name];
        }
    }

The problem is that when i write var sourceAcc = TypeAccessor.Create(sourceType); i get an instance of DynamicAccessor that does not support GetMembers method. So then when i call GetMembers method i get an exception (NotSupportedException).

I would like to know which is the proper way to enumarte public properties of an instance (given it's type)