✓ Accepted answer
The Archivable property of a Player prevents you from cloning it. You need to disable it first before cloning the character and then re-enable it back to its default property of false. I also added in a repeat until loop so that both the character and player load first before you try cloning the character. This is a common bug when running the script outside of studio. Also, in case you haven't used it, please post output of the script. You should've gotten an attempt to access nil value error which can narrow down where the bug is. To open the output window in studio go to view>output(one of the smaller buttons to the right of properties and explorer)
local Player, CHR
repeat
wait(.5)
Player = game.Players.LocalPlayer
CHR = Player.Character
until
(Player ~= nil) and (CHR ~= nil)
CHR.Archivable = true
local CHRclo = CHR:Clone()
CHR.Archivable = false
CHRclo.Parent = game.ServerStorage
Wiki page:
http://wiki.roblox.com/index.php?title=API:Class/Instance/Archivable