Loading a quote, passing it to the revision creation service and calling save errors with "ArgumentError: A copy of Revision::CreationService has been removed from the module tree but is still active!" when it tries to instantiate the mailer and I have no idea why.

application_mailer.rb

# frozen_string_literal: true

class ApplicationMailer < ActionMailer::Base
  helper :app_url
  helper :formatting

  default from: "Relay <app@#{Rails.configuration.incoming_mail_domain}>"
  layout "mailer"

  MAX_ATTACHMENT_SIZE = 20 * 1024 * 1024

  def reply_address(discussion)
    "Relay Platform <reply-#{discussion.id}@#{Rails.configuration.incoming_mail_domain}>"
  end

  def quote_address(quote)
    "Relay Platform <quote-#{quote.id}@#{Rails.configuration.incoming_mail_domain}>"
  end
end

quote_mailer.rb

# frozen_string_literal: true

class QuoteMailer < ApplicationMailer
  def invite_reinsurer
    @quote = params[:quote]
    @message = params[:message]
    @recipient = @quote.reinsurer
    attach(@quote.worksheet.documents)

    mail(
      to: @recipient.email,
      from: quote_address(@quote),
      subject: "#{@quote.worksheet.cedent.full_name} requested a quote from you",
    )
  end

  def quote_uploaded
    @quote = params[:quote]
    @message = params[:message]
    @recipient = @quote.worksheet.cedent
    attach(@quote.revisions.last&.documents)

    mail(
      to: @recipient.email,
      from: reply_address(@quote.discussion),
      subject: "#{@quote.reinsurer.full_name} uploaded a quote",
    )
  end

  def quote_confirmation
    @quote = params[:quote]
    @recipient = @quote.reinsurer

    mail(
      to: @recipient.email,
      from: reply_address(@quote.discussion),
      subject: "Your quote has been sent to #{@quote.worksheet.cedent.full_name}",
    )
  end

  def quote_accepted
    @quote = params[:quote]
    @recipient = @quote.reinsurer
    @message = params[:message]

    mail(
      to: @recipient.email,
      from: reply_address(@quote.discussion),
      subject: "#{@quote.worksheet.cedent.full_name} accepted your quote",
    )
  end

  def quote_rejected
    @quote = params[:quote]
    @recipient = @quote.reinsurer
    @message = params[:message]

    mail(
      to: @recipient.email,
      from: reply_address(@quote.discussion),
      subject: "#{@quote.worksheet.cedent.full_name} requested a new quote",
    )
  end

  private

  def attach(file_or_files)
    attachment_limit = MAX_ATTACHMENT_SIZE
    [file_or_files].flatten.compact.each do |attachment|
      if attachment.byte_size < attachment_limit
        attachment_limit -= attachment.byte_size
        attachments[attachment.blob.filename.to_s] = attachment.download
      else
        @attachments_excluded = true
      end
    end
  end
end

revision_slash_creation_service.rb

# frozen_string_literal: true

class Revision
  class CreationService
    MESSAGE_SUBJECT = "Quote Submitted"

    include ActiveModel::Validations

    attr_reader :quote, :params, :message, :files, :files_to_attach,
      :key_perils

    delegate :reinsurer, :worksheet, to: :quote

    validates :quote, presence: true
    validate :quote_can_transition
    validate :revision_is_valid

    def initialize(quote:, files:, files_to_attach: [], message: nil, **params)
      @quote = quote
      @files = files
      @params = params
      @files_to_attach = files_to_attach
      @key_perils = params[:key_perils]
      if message
        @message = quote.discussion.messages.build(
          author: reinsurer,
          subject: MESSAGE_SUBJECT,
          body: message,
        )
      end
    end

    def revision
      return if quote.blank?

      @revision ||= quote.revisions.build(documents: documents, **params)
    end

    def save
      if valid?
        ActiveRecord::Base.transaction do
          revision.save
          message&.save
          quote.receive_quote

          ZipRevisionDocumentsJob.perform_later(revision.id)
          QuoteMailer.with(quote: quote, message: message).quote_uploaded.deliver_later
          QuoteMailer.with(quote: quote).quote_confirmation.deliver_later
          worksheet.cedent.notification_events.create(
            event: quote.revisions.count == 1 ? "Quote.Created" : "Quote.Modified",
            triggered_by: reinsurer,
            relates_to: quote,
          )
        end
      end
    end

    private

    def documents
      files + documents_to_copy
    end

    def documents_to_copy
      existing_attachments = ActiveStorage::Attachment
        .includes(:blob)
        .where(id: files_to_attach.map { |f| f[:id] })

      existing_attachments.map(&:blob)
    end

    def revision_is_valid
      return if revision.blank?

      unless revision.valid?
        revision.errors.each do |key, error|
          errors.add(key, error)
        end
      end
    end

    def quote_can_transition
      return if quote.blank?

      errors.add(:quote, "must be ready to receive quote") unless quote.can_receive_quote?
    end
  end
end