I had to use the last update from ES2 to get it to work with the last release from Unity.
However it throw an exception on UWP (works fine in Editor and Android) when I use ES2.Save() and no file is created in the persistentDataPath (others plugins manage to write in this path);
ES2.Save("test","savetest.bin?tag=thisIsATest");TypeInitializationException: The type initializer for 'PDM' threw an exception.
ArgumentException: Path cannot be the empty string or all whitespace.
at System.IO.Directory.CreateDirectory(String path)
at ES2.Save[T](T param, String identifier)
at InitialisationScript.$Invoke0(Int64 instance, Int64* args)
at UnityEngine.Internal.$MethodUtility.InvokeMethod(Int64 instance, Int64* args, IntPtr method)
(Filename: <Unknown> Line: 0)
Is this a bug or is there a workaround ?