When calling;
game:GetService("StarterGui"):SetCore("ResetButtonCallback", false)
I get this error;
13:51:43.656 - SetCore: ResetButtonCallback has not been registered by the CoreScripts
13:51:43.656 - Stack Begin
13:51:43.657 - Script 'ReplicatedFirst.Loading', Line 2
13:51:43.657 - Stack End
13:52:09.069 - UnequipTools can only be called on a Humanoid with a corresponding Player object.

3 comments
Place the script in StarterGui and do the same .
@icapaz if you don't spawn the character right away the StarterGui doesn't load so they can reset themselfes into the game. You would have to spawn and kill them imediatly just to load the gui....
facepalm use wait()