game.Players.PlayerAdded:connect(function(plr)
plr.CharacterAdded:connect(function(char)
repeat wait() until char.Humanoid --Wait for the humanoid.
char.Humanoid.Died:connect(function(OMG)
char.Humanoid.WalkSpeed = 0
end)
end)
end)
I need the character to die or come in the server to change their walkspeed to 0 what am I doing wrong?

2 comments
It's kind of a prerequesite that you have a character to change its WalkSpeed. What exactly are you trying to do?
You're assuming that the Humanoid exists while trying to check if it exists, so you need to do 'char:FindFirstChild("Humanoid")', or 'char:WaitForChild("Humanoid")', which would probably be better, Other than that your code looks fine.