How would I fix the datastore issue with encoding?

I am trying to make a datastore that stores many values and I have been told to use JSONEnocde and Decode. I have the data in a table which the data is gained from replicatedStorage. I then JSONEncode the table and then save the encoded data. I then decode the data using JSONDecode once they enter back in the game and set the values of the replicatedStorage to the table that was decoded. I use a pcall function and get the error when I save and load data. I Get no error but the data does not save. Ideas?

--Get The Service's
local replicatedStorage = game:GetService("ReplicatedStorage")
local timePlayedValue = replicatedStorage.PlayerStats:WaitForChild("TimePlayedValue")
local totalTimeValue = replicatedStorage.PlayerStats:WaitForChild("TotalTimeValue")
local httpsService = game:GetService("HttpService")
local dsService = game:GetService("DataStoreService")
local mainStore = dsService:GetDataStore("MainDataStore")

--Get The Gameplay Stats
local CompletedMissionsValue = game:GetService("ReplicatedStorage").GamePlayStats:WaitForChild("CompletedMissionsValue")
local FailedMissionsValue = game:GetService("ReplicatedStorage").GamePlayStats:WaitForChild("FailedMissionsValue")
local PreviousMissionValue = game:GetService("ReplicatedStorage").GamePlayStats:WaitForChild("PreviousMissionValue")
local TimesDiedValue = game:GetService("ReplicatedStorage").GamePlayStats:WaitForChild("TimesDiedValue")
local TrapsAvoidedValue = game:GetService("ReplicatedStorage").GamePlayStats:WaitForChild("TrapsAvoidedValue")
local TrapsFailedValue = game:GetService("ReplicatedStorage").GamePlayStats:WaitForChild("TrapsFailedValue")

--Get The PlayerStats
local CoinsValue = replicatedStorage.PlayerStats:WaitForChild("Coins")
local DateFirstJoinedValue = replicatedStorage.PlayerStats:WaitForChild("DateFirstJoinedValue")
local RankValue = replicatedStorage.PlayerStats:WaitForChild("Rank")
local ExperienceValue = replicatedStorage.PlayerStats:WaitForChild("XP")

--Table To Store Data
local AllStatsTable = {
    CompletedMissionsValue.Value,FailedMissionsValue.Value,PreviousMissionValue.Value,TimesDiedValue.Value,TrapsAvoidedValue.Value,TrapsFailedValue.Value,
    CoinsValue.Value,DateFirstJoinedValue.Value,RankValue.Value,ExperienceValue.Value,totalTimeValue.Value
}

--Increment Time Values
incrementor = coroutine.create(function()
    while wait(1) do
        timePlayedValue.Value = timePlayedValue.Value + 1
        totalTimeValue.Value = totalTimeValue.Value + 1
    end
end)

coroutine.resume(incrementor)

game:GetService("Players").PlayerRemoving:Connect(function(player)
    local err,success = pcall(function()
        local jsonTable = httpsService:JSONEncode(AllStatsTable)
        mainStore:SetAsync(player.UserId,jsonTable)
    end)
    if err then
        print("error saving")
    end
end)

game:GetService("Players").PlayerAdded:Connect(function(player)
    local err,success = pcall(function()
        local jsonTable = mainStore:GetAsync(player.UserId)
        local data = httpsService:JSONDecode(jsonTable) 
        if data then
            print("data avaliable")
            data[1] = AllStatsTable[1]
        end

    end)
    if err then
        print("error loading")
    end
end)

The biggest problems I see are:

1. You've got the return values of pcall in the wrong order, it should be local success, err = pcall( not err, success

2. You have a coroutine that looks like it's meant to make test changes to your save data, but you never actually update the values in AllStatsTable. That table's values are set once from the value objects, and never again.

Also, consider pcall-ing the json encode and decode in isolation, so if something throws, you know if it's the json encode/decode or the datastore get/set.