I know Newstonsoft.Json doesn't work with Unity projects, but someone made a UnityJson, and it's giving me the same error.

Could not install package 'Unity.Newtonsoft.Json 7.0.0'. You are trying to install this package into a project that targets '.NETFramework,Version=v3.5,Profile=Unity Full v3.5', but the package does not contain any assembly references or content files that are compatible with that framework. For more information, contact the package author. 0

Using the NET 2.0 DLL since Unity doesn't support any higher. With the following code:

using Newtonsoft.Json;

public static class ItemDatabase {
    public static void Test() {
        ItemData boots = new ItemData {
            name = "Boots",
            description = "Keeps your feet warm",
            sprite = "boots"
        };
        ItemData[] dataArray = { boots };
        int[] intArray = { 1 };

        JsonConvert.SerializeObject(boots); // works
        JsonConvert.SerializeObject(dataArray); // crashes
        JsonConvert.SerializeObject(intArray); // works
    }
}

public struct ItemData {
    public string name;
    public string description;
    public string sprite;
}

When I serialize "ItemData" it works fine, but when I serialize an "ItemData" array Unity crashes. The log it dumps is cryptic so I don't know what's happening. I'm sure there are others out there using JSON.NET because that's what I see recommended here often, any ideas?