Image not changing and no output?

I'm trying to make a script for a UI that changes an icon dependent on a person's level. I get no output and no errors. I've tried deducting numbers to get the rbxasset and still nothing has worked.

Error happens on line 50 from then on.

wait()

_C = require( game:GetService("ReplicatedStorage").GameConfig )
_I = require( game:GetService("ReplicatedStorage").RankImgVariables )

local plr = game.Players.LocalPlayer
local chr = plr.Character or plr.CharacterAdded:Wait()
local hum = chr:WaitForChild("Humanoid",10)

lstats = plr:WaitForChild("leaderstats")
lvl = lstats:WaitForChild("Level")
exp = lstats:WaitForChild("XP")
gol = lstats:WaitForChild("Gold")

function addComas(str)
    return #str % 3 == 0 and str:reverse():gsub("(%d%d%d)", "%1,"):reverse():sub(2) or str:reverse():gsub("(%d%d%d)", "%1,"):reverse()
end

spawn(function()
    while wait() do
        if workspace:WaitForChild("PlayerHolder"):FindFirstChild(plr.Name) then
            chr = workspace:WaitForChild("PlayerHolder"):FindFirstChild(plr.Name) -- To update the character.
            hum = chr:WaitForChild("Humanoid")
        end
    end
end)

pcall(function()
    for _,v in ipairs(script:GetDescendants()) do
        if v.Name == "Color" then
            v.BackgroundColor3 = _C.UI_Color
        elseif v:IsA("TextButton") and v.BorderSizePixel > 0 then
            v.BorderColor3 = _C.UI_Color
        elseif v.Name == "PlayerImage" then
            v.Image = "https://www.roblox.com/headshot-thumbnail/image?userId="..plr.UserId.."&width=420&height=420&format=png"
        elseif v.Name == "PlayerName" then
            v.Text = string.upper(plr.Name)
        elseif v.Name == "PlayerLevel" then
            pcall(function() lvl.Changed:Connect(function() v.Text = "> "..addComas(tostring(lvl.Value)) end) end)
            v.Text = "> "..addComas(tostring(lvl.Value))
        elseif v.Name == "PlayerEXP" then
            pcall(function() exp.Changed:Connect(function() v.Text = "> "..addComas(tostring(exp.Value)).."/"..addComas(tostring(lvl.Value*25)) end) end)
            v.Text = "> "..addComas(tostring(exp.Value)).."/"..addComas(tostring(lvl.Value*250))
        elseif v.Name == "PlayerGold" then
            pcall(function() gol.Changed:Connect(function() v.Text = "> "..addComas(tostring(gol.Value)) end) end)
            v.Text = "> "..addComas(tostring(gol.Value))
        elseif v.Name == "PlayerSpeed" then
            pcall(function() hum:GetPropertyChangedSignal("WalkSpeed"):Connect(function() v.Text = "> "..hum.WalkSpeed.."/99" end) end)
            v.Text = "> "..hum.WalkSpeed.."/99"
        elseif v.Name == "LevelIcon" then
            pcall(function() lvl.Changed:Connect(function()
                if lvl.Value == 1  then
                v.LevelIcon.Image = "rbxassetid://2468821787"
                elseif lvl.Value == 2  then
                v.LevelIcon.Image = "rbxassetid://2468821787"
                elseif lvl.Value == 3  then
                v.LevelIcon.Image = "rbxassetid://2468821787"
                elseif lvl.Value == 4  then
                v.LevelIcon.Image = "rbxassetid://2468821787"
                elseif lvl.Value == 5  then
                v.LevelIcon.Image = "rbxassetid://2468821787"
                elseif lvl.Value == 6  then
                v.LevelIcon.Image = "rbxassetid://2468821787"
            else    
                print("User is not a level")
                end end) end)
    end
    end
end)

for _,v in pairs(script:FindFirstChild(_C.UI_Theme):GetChildren()) do
    v.Parent = script.Parent
end