Check the comment length.xml

<?xml version="1.0" encoding="UTF-8"?>
<custom-workflow>
  <after-destroy></after-destroy>
  <after-save></after-save>
  <author>voronyuk.m@3soft.ru</author>
  <before-destroy></before-destroy>
  <before-save>


@maxlength = 10000
@signal_label = case I18n.locale.to_s
          when 'ru'
            "[Этот текст будет удален автоматически при следующем нажатии Создать. Не удаляйте его вручную! (Проверка длины комментария, см. предупреждение выше).]\r"
          else
            "[This label will be removed during the next submitting. Do not delete or modify it manually! (Check the comment length, see warning above).]\r"
          end

need_warning = false
# need to check if notes property is nil or not because when we modify tasks from the issues list it is.
if !@current_journal.nil? &amp;&amp; !@current_journal.notes.nil? &amp;&amp; @current_journal.notes.length &gt; @maxlength
  owner_email = @issue.custom_field_value( CustomField.find_by_name('owner-email') )

  user_is_supportclient = false
  roles = @current_journal.user.roles_for_project(@issue.project)
  # user is a supportclient only if the author has assigned some role with
  # permission treat_user_as_supportclient enabled
  if roles.any? {|role| role.allowed_to?(:treat_user_as_supportclient) }
    user_is_supportclient = true
  end

  if !@current_journal.notes.include?(@signal_label) &amp;&amp; !@current_journal.notes.empty? &amp;&amp; !user_is_supportclient &amp;&amp; @current_journal.user_id.to_s != '2' &amp;&amp; !@issue.instance_variable_defined?(:@updated_by_email)
    need_warning = true
    @current_journal.notes = @signal_label + @current_journal.notes
  else
    need_warning = false
    @current_journal.notes.sub!(@signal_label, '') 
    @notes_length = @current_journal.notes.length
    @qty_truncated_symbols = @notes_length - @maxlength
    @current_journal.notes = @current_journal.notes[0, @maxlength-1] + case I18n.locale.to_s
          when 'ru'
            "... [оставшиеся #{@qty_truncated_symbols} символа были усечены]"
          else 
            "... [other #{@qty_truncated_symbols} symbols was truncated]"
          end
          
  end
end

if need_warning

  @warning_message = case I18n.locale.to_s
          when 'ru'
            "Предупреждение: Ваш комментарий длиннее #@maxlength символов (#{@current_journal.notes.length} символа). Пожалуйста, сократите его, иначе он будет усечен до #@maxlength символа автоматически."
          else
            "Warning: your note is longer than #@maxlength symbols (#{@current_journal.notes.length} symbols). Please make them shorter, else it will be truncated to #@maxlength symbols automatically. (debug info: locale = " + I18n.locale.to_s + ")"
          end
          
  raise WorkflowError, @warning_message
end  
</before-save>
  <created-at type="datetime">2020-09-04T06:42:27Z</created-at>
  <description>if the comment is too long (e.g. &gt;&gt;10000 symbols), the web server may break the connection by timeout.</description>
  <name>Check the comment length</name>
  <observable>issue</observable>
  <exported-at>2020-09-09T12:43:02Z</exported-at>
  <plugin-version>0.1.6</plugin-version>
  <ruby-version>2.0.0-p648</ruby-version>
  <rails-version>3.2.17</rails-version>
</custom-workflow>