BinaryImporter Internal Classes

Just a short question, I couldnt find any related posts to this:

In my code I have a

public class Test

and inside this class is another internal class:

public class Test {…
class Internal {…}

Both classes implement Savable and saving them is no problem, but as I try to load them I get an error saying accessing the constructor of Internal is not possible. As there is no problem with loading if I make Internal a normal public class I assume that the BinaryImporter (I use BinaryImporter/Export to Load/Save) cannot use the constructor of the internal class. Is there any (simple) way to make this work?

Make it a not internal class?
Probably the simplest way.

The issue is that when you have a non-static inner class then it can’t be instantiated on its own. You can only instantiate in the context of the outer instance.

In other words, this won’t work:
new Test.Inner();
…but this will:
Test test = new Test();
new test.Inner();

Reflection based frameworks will have a big problem with that.

…so the other option is to make it static and then it can be instantiated on its own.