OnServerEvent can only be used on the server?

ERROR: OnServerEvent can only be used on the server

LocalScript1:

--local Settings = require(game.ServerScriptService.Settings)

local plr = game.Players.LocalPlayer
local chat = game.ReplicatedStorage.ChatHistory
local last
local GroupId = 2642682 --Settings.Groupe.GroupId
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function newChat(msg,plr)
	if #msg > 0 then
		for i, c in pairs(chat:GetChildren()) do
			c.Position = c.Position - UDim2.new(0, 0, 0.1, 0)
		end
		local newMessage = script.Msg:clone()
		if #chat:GetChildren() == 6 then
			chat:GetChildren()[1]:Destroy()
		end
		if plr.TeamColor == BrickColor.new("Bright red") then
			newMessage.Text = "[RAIDER] "..plr.Name..": "..msg
			newMessage.Raider.Visible = true
			print(plr.Name.." is raider")
		else
			newMessage.Rank.Text = "["..plr:GetRoleInGroup(GroupId).."] "
			newMessage.Text = "["..plr:GetRoleInGroup(GroupId).."] "..plr.Name..": "..msg
			newMessage.Rank.Visible = true
		end
		newMessage.Visible = true
		newMessage.Parent = chat
		newMessage.Position = UDim2.new(0, 0, 0.6, 0)
		last = newMessage
		wait(60)
		last:Destroy()
	end
end

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function newChatServer(plr,msg)
	for i, c in pairs(chat:GetChildren()) do
		c.Position = c.Position - UDim2.new(0, 0, 0.1, 0)
	end
	local newMessage = script.Msg:clone()
	if #chat:GetChildren() == 6 then
		chat:GetChildren()[1]:Destroy()
	end
	newMessage.Rank.Text = "["..plr:GetRoleInGroup(GroupId).."] "
	newMessage.Text = "[SERVER] "..plr.Name..msg
	newMessage.Server.Visible = true
	newMessage.Visible = true
	newMessage.Parent = chat
	newMessage.Position = UDim2.new(0, 0, 0.6, 0)
	last = newMessage
	wait(60)
	last:Destroy()
end

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game.Players.LocalPlayer.Chatted:connect(function(msg)
	newChat(msg, plr) print("newChat")
	game.ReplicatedStorage.RemoteEvent.NewMsg:FireServer(plr, msg) print("FireChatService")
end)

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game:GetService("ReplicatedStorage").RemoteEvent.SwitchTeam.OnServerEvent:connect(function(plr)
	local msg = " switch team to "..plr.Team.Name.."!"
	newChatServer(plr,msg)
	game.ReplicatedStorage.RemoteEvent.NewMsg:FireServer(plr, msg) print("FireChatService")
end)

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LocalScript2:

script.Parent.MouseButton1Click:connect(function()
	game.Players.LocalPlayer.TeamColor = BrickColor.new("Bright red")
	------------------------------------------------------------------------
	game:GetService("ReplicatedStorage").RemoteEvent.LoadChar:FireServer() --game.Players.LocalPlayer:LoadCharacter()
	game:GetService("ReplicatedStorage").RemoteEvent.SwitchTeam:FireServer()
	------------------------------------------------------------------------
	print(game.Players.LocalPlayer.Name,"has changed team to",script.Parent.Name)
end)