Help, I can not understand the problem! What to do?????llllllllllllllllllllllll

Help, I can not understand what the problem is here.

local uis = game:GetService("UserInputService")
local rs = game:GetService("ReplicatedStorage")
local event = rs:WaitForChild("toolEvent") -- <

local plr = game.Players.LocalPlayer
local PressE = game.Workspace.tools.Key.Handle.Center.BillboardGui
attempt to index local 'char' (a nil value)

function search()
    local tools = workspace:WaitForChild("tools"):GetChildren()
    local min = nil
    local tool = nil

    for i = 1, #tools do
        local handle = tools[i]:FindFirstChild("Handle")
        if handle then
            local mag = (char.HumanoidRootPart.Position-handle.Position).magnitude
            if min == nil or mag < min then
                min = mag
                tool = tools[i]
            end
        end
    end

    if min then
        if min < 5 then
            return tool
        end
    end
end

uis.InputBegan:Connect(function(input, gameProcessed)
    if input.UserInputType.Name == "Keyboard" and gameProcessed == false then
        if input.KeyCode.Name == "E" then
            local tool = search()
            if tool then
                event:FireServer(tool)
                PressE.Enabled = false
            end
        end
    end
end)

while wait(1) do
    local tool = search()
    if tool then
        PressE.Enabled = true
    else
        PressE.Enabled = false
    end
end

Problem:

22:44:30.713 - Players.BITCr8ator.PlayerScripts.LocalScript:18: attempt to index local 'char' (a nil value) 22:44:30.738 - Stack Begin 22:44:30.738 - Script 'Players.BITCr8ator.PlayerScripts.LocalScript', Line 18 - global search 22:44:30.740 - Script 'Players.BITCr8ator.PlayerScripts.LocalScript', Line 46 22:44:30.741 - Stack End