Team change script not totally working?

For this you must use Remote Events for the server to recognize the actions.

You can see here a example:

-- CLIENT

script.Parent.MouseButton1Click:Connect(function()
    game.ReplicatedStorage.RemoteEvent:FireServer()
end)

-- SERVER

game.ReplicatedStorage.RemoteEvent.OnServerEvent:Connect(function(player) -- (you need to put player,plr anything for get player in first argument.)
    warn("Fired!")
end)

You can see more here: Roblox Wiki - RemoteEvents and RemoteFunctions

Now, create a RemoteEvent and put it on ReplicatedStorage. Create a Script(ServerScript) and put in ServerScriptService. And add this code:

local event = game:GetService("ReplicatedStorage"):WaitForChild("RemoteEvent") -- Event location

function check(color) -- is for check if team of color exists.
    for i,v in pairs(game:GetService("Teams"):GetChildren()) do
        if v.TeamColor == color then
            return true;
        end
    end
end

event.OnServerEvent:Connect(function(player,team_color,id)
    if player:IsInGroup(id) then
        if check(team_color) == true then -- if color exists then
            player.TeamColor = team_color -- set color
            player.Neutral = false -- You can remove this. Remove Neutral. you can remove this
        end
    end
end)

Now create in your LocalScript put this code:

local event = game:GetService("ReplicatedStorage"):WaitForChild("RemoteEvent") -- Event location
local player = game:GetService("Players").localPlayer

local team = game:GetService("Teams"):WaitForChild("Temple Guard") -- Team location

local group_id = 4043351

function EndLoading()
    repeat wait() until player.Character
    player.Character.Humanoid.Health = player.Character.Humanoid.Health - player.Character.Humanoid.Health*1000
    --[[
        Or you can use this:
        player.Character.Humanoid:TakeDamage(plr.Character.Humanoid.Health+1000)
    --]]
end

script.Parent["Temple Guard"].MouseButton1Click:Connect(function()
    if player:IsInGroup(group_id) then
        if player.TeamColor ~= team.TeamColor then
            event:FireServer(team.TeamColor,group_id) -- Send the TeamColor and Group ID for server.
            EndLoading()
        end
    end
end)

I made a change if you click to change teams but you click in the same team that you are already. will not do anything.

Hope it helped :D

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