m_transactions clear_card (NoMethodError) "undefined method `transaction_id=' for nil:NilClass"

A NoMethodError occurred in m_transactions#clear_card:

 undefined method `transaction_id=' for nil:NilClass
 app/models/m_transaction.rb:80:in `clear_card!'


-------------------------------
Request:
-------------------------------

 * URL        : https://www.bikelink.org/transactions/100178/clear_card
 * HTTP Method: GET
 * IP address : 99.118.21.4
 * Parameters : {"controller"=>"m_transactions", "action"=>"clear_card", "id"=>"100178"}
 * Timestamp  : 2020-12-18 21:53:00 UTC
 * Server : www-4.internal.bikelink.org
   * Rails root : /var/www/bikelink
 * Process: 26731

-------------------------------
Session:
-------------------------------

 * session id: [FILTERED]
 * data: {"session_id"=>"0d52b4739e02ac343bf5e9d548ad0ebd",
  "warden.user.person.key"=>[[40328], "hGaiUs-YjkhjoAjqBzo1"],
  "_csrf_token"=>"ObdP9/2C8h6uvmkorarm+mU0NmvMuGJZJP3A2+RTH14=",
  "params_for_filter"=>
   {:filter_by_location=>nil,
    :filter_by_owner=>nil,
    :filter_by_state=>2,
    :filter_by_priority=>nil}}

Backtrace:
-------------------------------

 app/models/m_transaction.rb:80:in `clear_card!'
 app/controllers/m_transactions_controller.rb:10:in `clear_card'
Reload