500 error in merge requests when trying open [production]

Good day, We have 500 error in merge requests on our production self-hosted gitlab-ce

sudo gitlab-rake gitlab:env:info

System information
System:		
Current User:	git
Using RVM:	no
Ruby Version:	2.4.4p296
Gem Version:	2.7.6
Bundler Version:1.16.2
Rake Version:	12.3.1
Redis Version:	3.2.11
Git Version:	2.17.1
Sidekiq Version:5.1.3
Go Version:	unknown

GitLab information
Version:	11.0.3
Revision:	aa62075
Directory:	/opt/gitlab/embedded/service/gitlab-rails
DB Adapter:	postgresql
URL:		https://git.example.ru
HTTP Clone URL:	https://git.example.ru/some-group/some-project.git
SSH Clone URL:	git@git.example.ruu:some-group/some-project.git
Using LDAP:	yes
Using Omniauth:	no

GitLab Shell
Version:	7.1.4
Repository storage paths:
- default: 	/var/opt/gitlab/git-data/repositories
Hooks:		/opt/gitlab/embedded/service/gitlab-shell/hooks
Git:		/opt/gitlab/embedded/bin/git

sudo gitlab-rake gitlab:check

Checking GitLab Shell ...

GitLab Shell version >= 7.1.4 ? ... OK (7.1.4)
Repo base directory exists?
default... yes
Repo storage directories are symlinks?
default... no
Repo paths owned by git:root, or git:git?
default... yes
Repo paths access is drwxrws---?
default... yes
hooks directories in repos are links: ... 
Administrator / tmp ... repository is empty
[...]
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Check GitLab API access: OK
Redis available via internal API: OK

Access to /var/opt/gitlab/.ssh/authorized_keys: OK
gitlab-shell self-check successful

Checking GitLab Shell ... Finished

Checking Sidekiq ...

Running? ... yes
Number of Sidekiq processes ... 1

Checking Sidekiq ... Finished

Reply by email is disabled in config/gitlab.yml
Checking LDAP ...

Server: ldapmain
not verifying SSL hostname of LDAPS server 'addmz1.corp.example.ru:636'
LDAP authentication... Success
LDAP users with access to your GitLab server (only showing the first 100 results)
	DN: cn=user_q,ou=users,ou=gk,dc=corp,dc=example,dc=ru	 sAMAccountName: user_q

Checking LDAP ... Finished

Checking GitLab ...

Git configured correctly? ... yes
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config up to date? ... yes
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory exists? ... yes
Uploads directory has correct permissions? ... yes
Uploads directory tmp has correct permissions? ... yes
Init script exists? ... skipped (omnibus-gitlab has no init script)
Init script up-to-date? ... skipped (omnibus-gitlab has no init script)
Projects have namespace: ... 

Administrator / tmp ... yes
[...]
Redis version >= 2.8.0? ... yes
Ruby version >= 2.3.5 ? ... yes (2.4.4)
Git version >= 2.9.5 ? ... yes (2.17.1)
Git user has default SSH configuration? ... yes
Active users: ... 255

Checking GitLab ... Finished

production.log

Started GET "/UNIAO/SOURCE/dataFlow/merge_requests/18" for 10.0.0.0 at 2018-07-06 10:06:56 +0300
Processing by Projects::MergeRequestsController#show as HTML
  Parameters: {"namespace_id"=>"UNIAO/SOURCE", "project_id"=>"dataFlow", "id"=>"18"}
Started GET "/DL-ompir-JavaGroup/centralreportdl/merge_requests/23.json?serializer=widget" for 10.0.0.0 at 2018-07-06 10:06:56 +0300
Processing by Projects::MergeRequestsController#show as JSON
  Parameters: {"serializer"=>"widget", "namespace_id"=>"DL-ompir-JavaGroup", "project_id"=>"centralreportdl", "id"=>"23"}
Completed 200 OK in 245ms (Views: 2.5ms | ActiveRecord: 26.9ms)
Completed 500 Internal Server Error in 1053ms (ActiveRecord: 44.4ms)

ActionView::Template::Error (undefined method `meta?' for nil:NilClass):
    1: - diff_file = discussion.diff_file
    2: - blob = discussion.blob
    3: - discussions = { discussion.original_line_code => [discussion] }
    4: - diff_file_class = diff_file.text? ? 'text-file' : 'js-image-file'
    5: - diff_data = {}
    6: - expanded = discussion.expanded? || local_assigns.fetch(:expanded, nil)
  lib/gitlab/diff/file.rb:54:in `line_code'
  lib/gitlab/metrics/instrumentation.rb:159:in `block in line_code'
  lib/gitlab/metrics/method_call.rb:36:in `measure'
  lib/gitlab/metrics/instrumentation.rb:159:in `line_code'
  app/models/diff_note.rb:85:in `original_line_code'
  app/models/concerns/discussion_on_diff.rb:8:in `original_line_code'
  app/views/discussions/_diff_with_notes.html.haml:3:in `_app_views_discussions__diff_with_notes_html_haml___712167936556832241_70014911332700'
  app/views/discussions/_discussion.html.haml:52:in `_app_views_discussions__discussion_html_haml__48369991542740413_70014910424160'
  app/views/shared/notes/_notes.html.haml:6:in `block in _app_views_shared_notes__notes_html_haml__2398181751678215897_70014910583540'
  app/views/shared/notes/_notes.html.haml:2:in `each'
  app/views/shared/notes/_notes.html.haml:2:in `_app_views_shared_notes__notes_html_haml__2398181751678215897_70014910583540'
  app/views/shared/notes/_notes_with_form.html.haml:6:in `_app_views_shared_notes__notes_with_form_html_haml___446451445812313364_70014909075240'
  app/views/projects/merge_requests/_discussion.html.haml:11:in `_app_views_projects_merge_requests__discussion_html_haml__541283208459500399_70014909450900'
  app/views/projects/merge_requests/show.html.haml:80:in `_app_views_projects_merge_requests_show_html_haml___2726066505541241849_70014899384200'
  app/controllers/projects/merge_requests_controller.rb:52:in `block (2 levels) in show'
  app/controllers/projects/merge_requests_controller.rb:34:in `show'
  lib/gitlab/i18n.rb:50:in `with_locale'
  lib/gitlab/i18n.rb:56:in `with_user_locale'
  app/controllers/application_controller.rb:362:in `set_locale'
  lib/gitlab/middleware/multipart.rb:95: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/middleware/rails_queue_duration.rb:22:in `call'
  lib/gitlab/metrics/rack_middleware.rb:15:in `block in call'
  lib/gitlab/metrics/transaction.rb:53:in `run'
  lib/gitlab/metrics/rack_middleware.rb:15:in `call'
  lib/gitlab/middleware/read_only/controller.rb:28:in `call'
  lib/gitlab/middleware/read_only.rb:16:in `call'
  lib/gitlab/request_context.rb:18:in `call'
  lib/gitlab/metrics/requests_rack_middleware.rb:27:in `call'
  lib/gitlab/middleware/release_env.rb:10:in `call'

2018-07-06-100914_719x607_scrot