Error occurring when sending an offer

[devisaah]

def send_offer
      account = Handler.new('********','********','shared_secret')

      me = account.normal_get_inventory('***************', 570)
      his = account.normal_get_inventory("Skanby")

      myarray = [me[5] , me[20] , me[60]].compact!
      theirarray = [his[1], his[20], his[30]].compact!

      # whenever
      account.send_offer(myarray,theirarray,"******************************************", "send offer!") 
end

When sending an offer the following error is occurring, what could it be?

[OmG3r]

There are few possibilities that come to mind for this issue:

Are you sure the trade link you are using is valid ?
can you inspect his[1] and make sure it is not gems, this library was not made with gems in mind.

[devisaah]

actually his [1] was coming from gems, I made other changes in relation to the code above where myarray put an item where it is exchangeable and now it is giving a different error, which I am not able to understand it.

def send offer 
      account = Handler.new('*******','**********')

      me = account.normal_get_inventory('*************', 570)
      his = account.normal_get_inventory("76561199093280846", 570)

      myarray = [me[7]].compact!
      theirarray = [].compact!

      # whenever
      trade_url = "https://steamcommunity.com/tradeoffer/new/?partner=1133015118&token=gL6cA2A6"
      account.send_offer(myarray, theirarray, trade_url)
end

[OmG3r]

that error is occurring due to [].compact!

here is the docs

if .compact! does not make any changes to an array it will return nil.

Since [] is already an empty array .compact! will not do any modification and return nil

steam-trade will raise an error if it does not recieve an Array or a Hash as a trade argument.

also please make sure your me[7] actually includes an item, otherwise you will encounter an error since you cannot send empty trade offers