I received an error 'Y55 : Related House Bill CCN-Related House Bill CCN cannot be related to 2 House Bill Close messages'. What does it mean?

I received an error 'Y55 : Related House Bill CCN-Related House Bill CCN cannot be related to 2 House Bill Close messages'. What does it mean?

Please be informed if you're changing the previous cargo control number: 

(Not Arrived)

Co-load with 8000 series

  1. Edit the correct Previous CCN in Housebill
  2. Save > *No need to Cancel Housebill just save changes.
  3. Go to Close Message
  4. Close Message – CANCEL
  5. Close Message – Edit to Correct Previous CCN
  6. Close Message – Send as ADD
Back to Back -9000 series
  1. Cancel Close Message
  2. Cancel Housebill
  3. Edit to correct CCN
  4. Resubmit as ADD ( Housebill and Close )