LitJson gives compile error on building for windows store

Guys i need help. i have been following this tutorial How to Read JSON Data in Unity (LitJSON) - YouTube
I want to save data so i imported LitJson and it all works fine in unity. but when i go to
build settings
and build for windows store im getting error CS1684. it says the reference
claims it is defined elsewhere and the second error(CS0011) says the base
class for LitJson could not be resolved.
How do i solve this?

I finally found this:

https://docs.unity3d.com/Manual/windowsstore-missingtypes.html

According to that, a lot of functions/classes are not supportend in a Windows-Store-App. Using Compiler-Directives, you can avoid the problem:

#if NETFX_CORE
   using XmlReader = WinRTLegacy.Xml.XmlReader;
#else
   using XmlReader = System.Xml.XmlReader;
#endif

Downside: Not all functions can easily be replaced. And (in this case) you need to edit the files of a 3rd-party-product.