Why did this script break when it worked before?

This script worked before but wont work now. I have no clue why.

a = game.Players.LocalPlayer.PlayerGui.Hacker.Frame

function clicked()

    local text = "<EoF";
for i = 1,#text do
    a.Mes1.Text = text:sub(1,i);
    wait(0.1);
end

    wait(1.5)
    local text = "LOADING LOCAL_COMPUTER_DATA";
for i = 1,#text do
    a.Mes2.Text = text:sub(1,i);
    wait(0.1);
end

    wait(1.5)
    local text = "HARD_DRIVE";
for i = 1,#text do
    a.Mes3.Text = text:sub(1,i);
    wait(0.1);
end

    wait(1.5)
    local text = "MONITER_FRAME";
for i = 1,#text do
    a.Mes4.Text = text:sub(1,i);
    wait(0.1);
end

    wait(1.5)
    local text = "FIREWALL_SECURITY";
for i = 1,#text do
    a.Mes5.Text = text:sub(1,i);
    wait(0.1);
end


script.Parent.MouseButton1Down:connect(clicked)
end