Redmine

Hi All,

I'm a fairly new on Redmine (and Ruby).

My redmine installation was running well, but in the last few days I'm getting a very strange error when loading messages from the forum module.
More strange, is the fact that A RELOAD of the web page, completes with NO ERROR.

Can someone give me a clue to what is happening?

Bellow are the relevant Informations:
--> My Environment:

Environment:
  Redmine version                3.4.6.stable
  Ruby version                   2.3.3-p222 (2016-11-21) [i386-mingw32]
  Rails version                  4.2.8
  Environment                    production
  Database adapter               Mysql2
SCM:
  Git                            2.17.1
  Filesystem                     
Redmine plugins:
  export_docx                    1.2.2
  issue_mail_with_attachments    0.1.0
  redmine_checklists             3.1.5
  redmine_ckeditor               1.1.5
  redmine_cms                    1.1.0
  redmine_dmsf                   1.6.1
  redmine_inventory_manager      0.9
  redmine_xls_export             0.2.1.t9

--> The Error from .log (First Get, an error, the a reload... with no error):

Started GET "/redmine/boards/8/topics/11" for 127.0.0.1 at 2018-09-17 16:01:51 +0100
Processing by MessagesController#show as HTML
  Parameters: {"board_id"=>"8", "id"=>"11"}
  Current user: ***** (id=1)
  Rendered messages/show.html.erb within layouts/base (143.0ms)
Completed 500 Internal Server Error in 192ms (ActiveRecord: 40.0ms)

ActionView::Template::Error (Object must be a Date, DateTime or Time object. :label_board_plural given.):
    1: <%= board_breadcrumb(@message) %>
    2: 
    3: <div class="contextual">
    4:     <%= watcher_link(@topic, User.current) %>
  app/helpers/boards_helper.rb:23:in `board_breadcrumb'
  app/views/messages/show.html.erb:1:in `_app_views_messages_show_html_erb__649822366_70382136'
  lib/redmine/sudo_mode.rb:63:in `sudo_mode'
  plugins/redmine_dmsf/lib/redmine_dmsf/webdav/custom_middleware.rb:62:in `call'

Started GET "/redmine/boards/8/topics/11" for 127.0.0.1 at 2018-09-17 16:01:53 +0100
Processing by MessagesController#show as HTML
  Parameters: {"board_id"=>"8", "id"=>"11"}
  Current user: ***** (id=1)
  Rendered attachments/_form.html.erb (2.0ms)
  Rendered messages/_form.html.erb (5.0ms)
  Rendered messages/show.html.erb within layouts/base (23.0ms)
Completed 200 OK in 135ms (Views: 64.8ms | ActiveRecord: 59.1ms)