FuelSDK Create Triggered Send API failing with error code 2

Question

I tried to create a triggered send definition, but it's failing. The same code worked with a different account. Is it possible that the new account has Triggered Sends disabled somehow (is that is even possible?)

I get the following error:

{
    :create_response=>{
        :results=>{
            :status_code=>"Error",
            :status_message=>"Exception occurred during [CreateTriggeredSendDefinition] ErrorID: 1548827669",
            :ordinal_id=>"0",
            :error_code=>"2",
            :new_id=>"0",
            :object=>{
                :partner_key=>nil,
                :object_id=>nil,
                :customer_key=>"xxx",
                :name=>"Triggered Send - xxx Shared-link Trigger",
                :description=>"xxx Shared-link triggered send email.",
                :send_classification=>{
                    :partner_key=>nil,
                    :object_id=>nil,
                    :customer_key=>"Default Transactional"
                },
                :email=>{
                    :partner_key=>nil,
                    :id=>"45100985",
                    :object_id=>nil
                },
                :auto_add_subscribers=>true,
                :"@xsi:type"=>"TriggeredSendDefinition"
            }
        },
        :request_id=>"f5d88e80-4ba4-42b8-9098-57b576c15523",
        :overall_status=>"Error",
        :@xmlns=>"http://exacttarget.com/wsdl/partnerAPI"
    }
}

What could cause this error and how can I possibly fix it?

The code that I execute to create it:

  sdk = FuelSDK::TriggeredSend.new
  sdk.authStub = @client

  sdk.props = {
    "CustomerKey" => customer_key,
    "Name" => "Triggered Send - #{triggered_send_name}",
    "Description" => description,
    "Email" => {'ID' => email_id},
    "SendClassification" => {"CustomerKey" => send_classification_customer_key},
    "AutoAddSubscribers" => true,
    # "TriggeredSendStatus" => "Inactive"
  }

 sdk.props["List"] = {'ID' => list_id_to_add_subscribers_to}

 result = sdk.post   # Post to create if it didn't.