Why is my gui not popping up when it is enabled in the script?

So I am having this problem where the gui wont pop up at all, it is suppose to pop up for everyone but it does not, I dont know if it is a new roblox update that broke the script. But it work perfectly like 6 days ago. So can someone help me please?

Code:

local StoneBars = game.Workspace.StoneBars:GetChildren()

wait(15)
game.Workspace.Boss1Sound:Play()
game.ReplicatedStorage.Bosses.Boss1.Parent = workspace
game.Workspace.SchoolKids.Parent = game.ReplicatedStorage.OtherStuff
for i,v in pairs(StoneBars) do
    v.Transparency = 0
    v.CanCollide = true
end
if game.Workspace.StoneBars:FindFirstChild("DefensePart1") and game.Workspace.StoneBars:FindFirstChild("DefensePart2") then
    game.Workspace.StoneBars:FindFirstChild("DefensePart1").Transparency = 1
    game.Workspace.StoneBars:FindFirstChild("DefensePart2").Transparency = 1
end
wait(70)
for i,v in pairs(game.Players:GetPlayers()) do
    v.PlayerGui:FindFirstChild("BossName").Enabled = true
    v.PlayerGui:FindFirstChild("BossName").NameText.Text = "MEGA SCHOOL KID HAS ARRIVED!"
    wait(2.1)
    v.PlayerGui:FindFirstChild("BossName").NameText:TweenPosition(UDim2.new(0.325, 00.014, 0),Enum.EasingDirection.Out,Enum.EasingStyle.Linear,2)
    v.PlayerGui:FindFirstChild("BossName").NameText.Text = "DEFEAT MEGA SCHOOL KID!"
    v.PlayerGui:FindFirstChild("BossName").Enabled = false
end
game.ReplicatedStorage.OtherStuff.SchoolKids.Parent = workspace
game.Workspace.Boss1Sound:Stop()
for i,v in pairs(game.Players:GetPlayers()) do
    v.PlayerGui:FindFirstChild("Health"):Clone().Parent = v.PlayerGui
    v.PlayerGui:FindFirstChild("Health"):Destroy()
    v.PlayerGui:FindFirstChild("BossName").NameText.Text = "YOU FAILED!!!"
    wait(3)
    v.PlayerGui:FindFirstChild("BossName"):Clone().Parent = v.PlayerGui
    v.PlayerGui:FindFirstChild("BossName"):Destroy()
end
for i,v in pairs(StoneBars) do
    v.Transparency = 1
    v.CanCollide = false
end
wait(20)
if game.Workspace.StoneBars:FindFirstChild("DefensePart1") and game.Workspace.StoneBars:FindFirstChild("DefensePart2") then
    game.Workspace.StoneBars:FindFirstChild("DefensePart1").Transparency = 1
    game.Workspace.StoneBars:FindFirstChild("DefensePart2").Transparency = 1
end
for i,v in pairs(game.Players:GetPlayers()) do
    v.PlayerGui:FindFirstChild("BossName").NameText.Text = "Bonus Event!"
    wait(3)
    v.PlayerGui:FindFirstChild("BossName").NameText.Text = "Event: Find the MEGA chest to get coins!"
end
game.ReplicatedStorage.Chests["MEGA Chest"].Parent = workspace
wait(1)
local model = game.Workspace:WaitForChild("MEGA Chest")
model:MoveTo(Vector3.new(225.205, 15.292, 222.907))