Why isn't MouseClick working?

First, code:

script.Parent.ClickDetector.MouseClick:connect(function(player)
    print("clicked! by player " .. player.Name)
    for _, v in pairs(player.Character:GetChildren()) do
        print("iterating through player")
        if v:IsA("Shirt") then
            print("found shirt at " .. v:GetFullName() .. " with current ShirtTemplate " .. v.ShirtTemplate)
            v.ShirtTemplate = script.Parent.Parent.Shirt.ShirtTemplate
            print("changed shirt at " .. v:GetFullName() .. " to ShirtTemplate " .. v.ShirtTemplate)
        elseif v:IsA("Pants") then
            print("found pants at " .. v:GetFullName() .. " with current PantsTemplate " .. v.PantsTemplate)
            v.PantsTemplate = script.Parent.Parent.Pants.PantsTemplate
            print("changed pants at " .. v:GetFullName() .. " to PantsTemplate " .. v.PantsTemplate)
        end
    end
end)

This script is placed inside the Torso of a Humanoid model wearing a Shirt and Pants. My aim is to have the player click the Torso to put on the clothes.

It's as if the event isn't even firing - the first print statement doesn't show up in the console in online mode, whereas in Play Solo mode it functions fine.

It's in a Script, and Filtering is enabled.

I'm very puzzled right now. Any and all help would be greatly appreciated.