So when a player joins it should fire a client but in the client it says that i cannot find the left hand . This is server script
local replicatedstorage = game:GetService("ReplicatedStorage")
game.Players.PlayerAdded:Connect(function(plr)
replicatedstorage.Remotes.JustARandomWeld:FireClient(plr)
end)
Local Script
local replicatedstorage = game:GetService("ReplicatedStorage")
local gloves = replicatedstorage.Objects
local remote = replicatedstorage.Remotes.JustARandomWeld
remote.OnClientEvent:Connect(function(plr)
local leftweld = Instance.new("Weld")
local gloveleft = replicatedstorage.Objects.LeftArmGloves:Clone()
gloveleft.Position = game.Players.LocalPlayer.Character.LeftLowerArm
leftweld.C0 = game.Players.LocalPlayer.Character.LeftLowerArm
leftweld.C1 = gloveleft.WeldPart
end)

4 comments
Your error is in localscript on 5 line. You dont need to type plr after function. plr that you typed in FireClient from server its info for the server what client will be fired. Just remove it in localscript
LeftHand or LeftLowerArm?
yeah but @HaveASip when i remove it it says "Argument 1 missing". And its ment to be leftlowerarm yes
the problem is on line 5 in the localscript, simply remove "plr" from the function and it will work