Variables not working like they usually do?

I'm working on a script to make footprints in snow. I get an error at all of the l variables in square brackets (Ex: unexpected "[" at line 14), I'm not sure what I'm doing wrong because they usually work for sorting through tables.

There's probably some other problems in there as well so any help with those would be great.

local GlobalFrequency = 10

while true do
    local TickA = elapsedTime()
    wait(1/GlobalFreqency)
    local Surface = game.Workspace.ImprintableMap:GetChildren()
    local Char = game.Workspace:GetChildren()
    for i=1,#Char do
        if not Char[i]:FindFirstChild("Humanoid") then
            table.remove(Char, i)
        end
    end
    for i=1,#Surface do
        for l=1,#Char do
            local DetectDistance[l] = (Surface[i].position - Char[l].HumanoidRootPart.Position).magnitude
        end
        local DetectDistance = math.min(DetectDistance)
        if DetectDistance >= (Surface[i].Size.X + Surface[i].Size.Z)/2 + 5 then
            table.remove(Surface[i])
        end
    end
    if DetectDistance ~= nil and math.min(Surface.TriangleCount) <= 4980 then
        for i=1,#Char do
            for l=1,#Surface do
                local x[1] = Char[i].LeftFoot:clone()
                x[1]:ClearAllChildren()
                x[1].name = CharSub[i + l]
                x[1].parent = game.Workspace.ImprintableMap
                local x[2] = Char[i].LeftLowerLeg:clone()
                x[2]:ClearAllChildren()
                x[2].name = CharSub[i + l + 1]
                x[2].parent = game.Workspace.ImprintableMap
                local x[3] = Char[i].LeftUpperLeg:clone()
                x[3]:ClearAllChildren()
                x[3].name = CharSub[i + l]
                x[3].parent = game.Workspace.ImprintableMap
                local x[4] = Char[i].RightFoot:clone()
                x[4]:ClearAllChildren()
                x[4].name = CharSub[i + l]
                x[4].parent = game.Workspace.ImprintableMap
                local x[5] = Char[i].RightLowerLeg:clone()
                x[5]:ClearAllChildren()
                x[5].name = CharSub[i + l + 1]
                x[5].parent = game.Workspace.ImprintableMap
                local x[6] = Char[i].RightUpperLeg:clone()
                x[6]:ClearAllChildren()
                x[6].name = CharSub[i + l]
                x[6].parent = game.Workspace.ImprintableMap
                local Imprint = Surface[l]:SubtractAsync(x)
                Imprint.name = SnowPlane
                Imprint.parent = game.Workspace.ImprintableMap
            end
        end
    else
        print("Unspecified Error")
    end
    local TickB = elapsedTime()
    -- Remove this debugging code --
    print(TickB - TickA .. "ms")
    break
end

I'm thinking it could be because im using l instead of i for the variable but I don't see any other way I could do it.