Error 500 in Gitlab Wiki after update to 9.5.4

Hi,

I’ve done the update to 9.5.4 yesterday. Everthing works fine. It was a little update from 9.4.? (I don’t remember)

The Problem is now that an existing Wiki for an existing Project will not work anymore. It always returns the Gitlab 500 Error Page. Empty (new) Wikipages for other projects still working and I can create and update there new pages.

Unfortunately I have no clue which Logfile to take to trace this error or give more detailed informations.

Hope for help. The wiki was proper filled!
Thanks,

Tom

I found in gitlab-rails/production.log the following

==> gitlab-rails/production.log <==
Started GET "/dmgmnt/dmgmnt-central/wikis/home" for 192.168.80.11 at 2017-09-20 09:19:33 +0200
Processing by Projects::WikisController#show as HTML
  Parameters: {"namespace_id"=>"dmgmnt", "project_id"=>"dmgmnt-central", "id"=>"home"}
Completed 500 Internal Server Error in 37ms (ActiveRecord: 0.6ms)

ActionView::Template::Error (failed stat - '/var/opt/gitlab/git-data/repositories/dmgmnt/dmgmnt-central.wiki.git/objects/65/272187975d9bee637c4ceec3f0bb7ce6b5f794' is locked: Permission denied):
    14:     %span.wiki-last-edit-by
    15:       Last edited by
    16:       %strong
    17:         #{@page.commit.author.name}
    18:       #{time_ago_with_tooltip(@page.commit.authored_date)}
    19: 
    20:   .nav-controls
  app/models/wiki_page.rb:134:in `versions'
  app/models/wiki_page.rb:138:in `commit' 
  app/views/projects/wikis/show.html.haml:17:in `_app_views_projects_wikis_show_html_haml__4372144819085594815_70226241636360'
  app/controllers/projects/wikis_controller.rb:16:in `show'
  lib/gitlab/i18n.rb:46:in `with_locale'
  lib/gitlab/i18n.rb:52:in `with_user_locale'
  app/controllers/application_controller.rb:326:in `set_locale'
  lib/gitlab/middleware/multipart.rb:93:in `call'
  lib/gitlab/request_profiler/middleware.rb:14:in `call'
  lib/gitlab/middleware/go.rb:17:in `call'
  lib/gitlab/etag_caching/middleware.rb:11:in `call'
  lib/gitlab/request_context.rb:18:in `call'
  lib/gitlab/metrics/requests_rack_middleware.rb:27:in `call'

The desribed file have git owner rights

-r--r--r-- 1 git git 153 Sep 14 12:02 objects/65/272187975d9bee637c4ceec3f0bb7ce6b5f794

If I change it to chmod 666 and reload my wiki, it works again.

But I’ve still no idea what’s going wrong there.