attempt to get length of a number value how do i fic this?

trying to make a random map select but i keep geting this error "ServerScriptService.MainScript:39: attempt to get length of a number value - Server - MainScript:39"

local AvailableMaps = mapsFolder:GetChildren()

local ChosenMap = AvailableMaps[math.ramdom(1,#2)]

Status.Value = ChosenMap.Name.." Chosen"

local ClonedMap = ChosenMap:Clone()
ClonedMap.Parent = workspace 

this dosnt work

local AvailableMaps = mapsFolder:GetChildren()

local ChosenMap = AvailableMaps[math.ramdom(1,#AvailableMaps)]

Status.Value = ChosenMap.Name.." Chosen"

local ClonedMap = ChosenMap:Clone()
ClonedMap.Parent = workspace 

and this give me "ServerScriptService.MainScript:39: attempt to call a nil value - Server - MainScript:39"

any help or suggestions would be greatly apresiated

also 39 would be line 2 in this

sorry for spelling and formating