The error in the question, is what repeatedly shows up in this script that is supposed to make a player's speed equal to their leaderstats value.
local player = game:GetService("Players").LocalPlayer
local char = player.Character
player.leaderstats.Speed.Changed:connect(function()
char.Humanoid.WalkSpeed = player.leaderstats.Speed.Value + 16
end)

6 comments
Have you tried print debugging?
Maybe try adding a wait() to the beginning? Without more details on how leaderstats is being created, I can't help you much.
player:WaitForChild("leaderstats"):WaitForChild("Speed").Changed:Connect(function() (make sure that the Speed IntValue is actually in leaderstats, not in the player)
I already told him that haha. @iddash. But he's using a serverscript so he shouldn't use localplayer.
o kl mb
ok so what these comments are telling me is i should try using waitforchild on all of them, make sure int value is in leaderstats, and this is meant to be a serverscript