i was making a script in the server script service that removes the gui after 5 seconds the error i got is KeyDownGui is not a valid member of Startergui Heres the script
if game.ChildAdded then --- checks if the player is added
wait(5)
game.StarterGui.KeyDownGui:remove()
end

4 comments
Your description does not match your code. You're not 'cycling' through Players (as that implies a loop), but the end result does match OP's goal.
Originally It was going to be a for loop, but I just changed it to be worded correctly.
dosent work
Not quite sure what you mean. I just tested it and it works perfectly. Try placing it in ServerScriptService as a Script