Add UWP workaround to README

Author: veblush

README.md

@@ -63,6 +63,9 @@ Detailed Description is [here](./docs/UnitTest.md) to tell you what failed and w
 This library is tested on Unity 4.7, 5.2 and 5.3. For AOT environment like iOS, you
 need to use IL2CPP instead of obsolute Mono-AOT because IL2CPP handles generic code better than Mono-AOT. With Mono-AOT configuration, AOT related exception would be thrown.
 
+For windows store build, there is a compatibility issue related with UWP.
+If you have a problem, please read [workaround for UWP](./docs/UwpWorkaround.md).
+
 ## FAQ
 
  - Q: App stops throwing MissingMethodException for ComponentModel.TypeConverter like this.

docs/UwpWorkaround.md

@@ -0,0 +1,43 @@
+# Workaround for UWP (Universal Windows Platform)
+
+Latest windows store uses UWP for building an app.
+Unlike regular Unity apps, app for UWP uses dedicated .NET framework which is
+not compatible with Unity3D-Mono framework.
+
+## What's the problem?
+
+When you try to build app using Json.NET.Unity3D for Windows Store,
+you will get following errors:
+
+```
+UnityException: Failed to run serialization weaver with command ...
+(stripped)
+
+Mono.Cecil.ResolutionException:
+  Failed to resolve System.Runtime.Serialization.Formatters.FormatterAssemblyStyle
+(stripped)
+```
+
+UAP doesn't have enum `FormatterAssemblyStyle` in its assembly and
+it should be added to run on windows store.
+
+## How to fix?
+
+It's simple. Use original [Newtonsoft.Json](https://www.nuget.org/packages/Newtonsoft.Json/)
+which contains a DLL for UWP.
+
+  1. Import [Json.Net.Unity3D](https://github.com/SaladLab/Json.Net.Unity3D/releases/download/8.0.3/JsonNet.8.0.3.unitypackage)
+     unity package.
+  1. Create `Assets/UnityPackages/JsonNet/Portable` directory in unity project.
+  1. Download [Newtonsoft.Json](https://www.nuget.org/api/v2/package/Newtonsoft.Json/8.0.3)
+     nuget package and extract it as a zip file.
+  1. Copy `./lib/portable-net45%2Bwp80%2Bwin8%2Bwpa81%2Bdnxcore50/Newtonsoft.Json.dll`
+     in the nuget package to `Assets/UnityPackages/JsonNet/Portable` directory.
+  1. Watch `Assets/UnityPackages/JsonNet/Newtonsoft.Json.dll` with an inspector,
+     uncheck `Any Platform` at Select platforms for plugin
+     and Set all platforms checked except `WSAPlayer`.
+  1. Watch `Assets/UnityPackages/JsonNet/Portable/Newtonsoft.Json.dll` with an inspector,
+     uncheck `Any Platform` at Select platforms for plugin
+     and set only `WSAPlayer` checked.
+
+Done!