Why does this return an empty folder?

Ok, so the function for turning the data into a folder and value based hierarchy works perfectly. However the problem is that when you go to parse that back into a dictionary you are making an error. The problem is you are looping through the top folder and only inserting data if the children are values. That's why see nothing in the folder because it excludes other folders and there are only folders in the top level. To solve this you should apply what you did in the unload function. Just use recursion and treat the folders as the tables and convert them. Heres my solution:

local DSService = game:GetService('DataStoreService'):GetDataStore('WOOPPOLICE1')
local HttpService = game:GetService('HttpService')

local defaultData = {
    PlayerStats = {
        Name = "None",
        Title = "None",
        Rank = "None",
        Race = "None",
        Birth = "None",
        Shirt = "None",
        Pants = "None",
        Class = "None",
        Lives = 5,
        Days = 0,
        Money = 0,
        Karma = 0,
        Gender = "None",
        LastRewardTick = "",
        }, 
    Skills = {
        Skill1 = {
            SkillEXP = 0,
            SkillLevel = 1,
            SkillRank = "Novice",           
        },
    },
    Equipment = {
        Armor = "None",
        MainHand = "None",
        OffHand = "None",
        Epautlet = "None",
    },
    Inventory = {
        Tools = {},
        Materials = {},     
    }
}

local function buildDataEntryFromFolder(folder)

    local function recursive(folder)
        local parentTable = {}
        for key,value in pairs(folder:GetChildren()) do -- go through all the primary children of the folder first
             if value:IsA("ValueBase") then
                  parentTable[key] = value.Value -- if is a normal value put it in its assigned data table
             elseif value:IsA("Folder") then
                local t = recursive(value)
                parentTable[key] = t -- treat folder like a new table
            end
        end
        return parentTable
    end
    local dataEntry = recursive(folder)
        -- i hope this makes sense how i kind of reversed the recursion process in the unloadData function
    return dataEntry
end

function unloadData(player, data)
    local newDataFolder = Instance.new("Folder", player)
    newDataFolder.Name = "PlayerData"
    local function recursive(folder, children)
        for x, y in pairs (children) do
            if typeof(y) == 'table' then
                local newFolder = Instance.new("Folder", folder)
                newFolder.Name = x
                recursive(newFolder, y)
            elseif typeof(y) == 'number' then
                local value = Instance.new("NumberValue", folder)
                value.Name = x
                value.Value = y
            elseif typeof(y) == 'string' then
                local value = Instance.new("StringValue", folder)
                value.Name = x
                value.Value = y
            elseif typeof(y) == 'boolean' then
                local value = Instance.new("BoolValue", folder)
                value.Name = x
                value.Value = y
            else
                local value = Instance.new("StringValue", folder)
                value.Name = x
                value.Value = y
            end
        end
    end
    recursive(newDataFolder, data)
end

local function savePlayerData(player)
    local dataEntry = buildDataEntryFromFolder(player.PlayerData)
    DSService:SetAsync(player.UserId, dataEntry)
end

local function loadPlayerData(player)
    local dataEntry = DSService:GetAsync(player.UserId)

    --  In case there's no data found for the player, construct the data folder from a blank template
    if not dataEntry then
        dataEntry = defaultData
    end

    unloadData(player, dataEntry)

end

game.Players.PlayerAdded:Connect(function(player)
    loadPlayerData(player)
end)

game.Players.PlayerRemoving:Connect(function(player)
    savePlayerData(player)
end)

Your save data was messed up, heres your fix (look into buildDataEntryFromFolder)

local DSService = game:GetService('DataStoreService'):GetDataStore('WOOPPOLICE1')

local defaultData = {
    PlayerStats = {
        Name = "None",
        Title = "None",
        Rank = "None",
        Race = "None",
        Birth = "None",
        Shirt = "None",
        Pants = "None",
        Class = "None",
        Lives = 5,
        Days = 0,
        Money = 0,
        Karma = 0,
        Gender = "None",
        LastRewardTick = "",
        }, 
    Skills = {
        Skill1 = {
            SkillEXP = 0,
            SkillLevel = 1,
            SkillRank = "Novice",           
        },
    },
    Equipment = {
        Armor = "None",
        MainHand = "None",
        OffHand = "None",
        Epautlet = "None",
    },
    Inventory = {
        Tools = {},
        Materials = {},     
    }
}

local function buildDataEntryFromFolder(folder)

    local dataEntry = {}

    local total = 0
    recursive = function(tFolder, pFolder) --tableFolder, parentFolder

        for _, data in pairs(pFolder:GetChildren()) do

            print(data, data:IsA("ValueBase"), data:IsA("ValueBase") and data.Value or false)
            tFolder[data.Name] = data:IsA("ValueBase") and data.Value or {}

            if #data:GetChildren() > 0 then

                recursive(tFolder[data.Name], data)

            end

        end

    end

    recursive(dataEntry, folder)

    return dataEntry

end

function unloadData(Player, tFolder)

    Instance.new("Folder", Player).Name = "PlayerData"

   function recursive(folder, children)
        for k, v in pairs(children) do

            local child = Instance.new(typeof(v), folder)
            child.Name = k

            if type(v) ~= "table" then
                child.Value = v
            else
                recursive(child, v)
            end

        end
    end

    recursive(Player.PlayerData, tFolder)

end

local function savePlayerData(player)
    local dataEntry = buildDataEntryFromFolder(player.PlayerData)
    local success, err = pcall(function() DSService:SetAsync(player.UserId, dataEntry) end)

    if success then
        print("Saved Successfully")
    else
        print("Error: " .. err)
    end

end

local function loadPlayerData(player)

    local dataEntry = DSService:GetAsync(player.UserId)

    --  In case there's no data found for the player, construct the data folder from a blank template
    if not dataEntry then
        dataEntry = defaultData
    end

    unloadData(player, dataEntry)

end

game.Players.PlayerAdded:Connect(loadPlayerData)

game.Players.PlayerRemoving:Connect(savePlayerData)