Local users works just fine but LDAP users does not work.

Installed packages.

ii foreman 1.14.2-1 amd64 Systems management web interface
ii foreman-compute 1.14.2-1 all metapackage providing fog dependencies for Foreman,
ii foreman-debug 1.14.2-1 all provides support utility foreman-debug.
ii foreman-ec2 1.14.2-1 all metapackage providing EC2 dependencies for Foreman
ii foreman-libvirt 1.14.2-1 all metapackage providing libvirt dependencies for Foreman
ii foreman-postgresql 1.14.2-1 all metapackage providing PostgreSQL dependencies for Foreman
ii foreman-proxy 1.14.2-1 all RESTful proxies for DNS, DHCP, TFTP, and Puppet
ii foreman-sqlite3 1.14.2-1 all metapackage providing sqlite dependencies for Foreman
ii ruby-foreman-ansible 1.4.4-1 all Foreman Ansible plugin
ii ruby-foreman-deface 1.0.2-2 all Foreman Deface Plugin Dependency
ii ruby-foreman-discovery 8.0.1-1 all Foreman Discovery Plugin
ii ruby-foreman-docker 3.0.0-1 all Foreman Docker compute resource
ii ruby-foreman-salt 8.0.1-1 all Foreman Salt Plugin
ii ruby-foreman-tasks 0.8.6-1 all Tasks management engine for Foreman.
ii ruby-foreman-templates 4.0.1-1 all Foreman Templates Plugin

I run this on Ubuntu 16.04 LTS amd64.

I get the following error:

2017-03-14T10:29:03 d45e6a3f [app] [D] Setting current user thread-local variable to nil
2017-03-14T10:29:03 d45e6a3f [app] [D] Setting current user thread-local variable to foreman_admin
2017-03-14T10:29:03 d45e6a3f [app] [I] Expire fragment views/tabs_and_title_records-4 (0.2ms)
2017-03-14T10:29:03 d45e6a3f [app] [D] Setting current user thread-local variable to nil
2017-03-14T10:29:03 d45e6a3f [app] [W] Action failed | NoMethodError: undefined method `each' for nil:NilClass | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/ldap_fluff-0.4.6/lib/ldap_fluff/posix_member_service.rb:22:in `find_user_groups' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/ldap_fluff-0.4.6/lib/ldap_fluff/generic.rb:37:in `groups_for_uid' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/ldap_fluff-0.4.6/lib/ldap_fluff/ldap_fluff.rb:48:in `block in group_list' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/ldap_fluff-0.4.6/lib/ldap_fluff/ldap_fluff.rb:94:in `block in instrument' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/notifications.rb:164:in `block in instrument' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/notifications/instrumenter.rb:20:in `instrument' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/notifications.rb:164:in `instrument' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/ldap_fluff-0.4.6/lib/ldap_fluff/ldap_fluff.rb:93:in `instrument' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/ldap_fluff-0.4.6/lib/ldap_fluff/ldap_fluff.rb:47:in `group_list' | /usr/share/foreman/app/models/auth_sources/auth_source_ldap.rb:122:in `update_usergroups' | /usr/share/foreman/app/models/user.rb:202:in `block in try_to_login' | /usr/share/foreman/app/models/concerns/foreman/thread_session.rb:72:in `as' | /usr/share/foreman/app/models/concerns/foreman/thread_session.rb:78:in `as_anonymous_admin' | /usr/share/foreman/app/models/user.rb:194:in `try_to_login' | /usr/share/foreman/app/controllers/users_controller.rb:73:in `login' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_controller/metal/implicit_render.rb:4:in `send_action' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/abstract_controller/base.rb:198:in `process_action' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_controller/metal/rendering.rb:10:in `process_action' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/abstract_controller/callbacks.rb:20:in `block in process_action' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:117:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:555:in `block (2 levels) in compile' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:505:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:498:in `block (2 levels) in around' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:313:in `block (2 levels) in halting' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/rails-observers-0.1.2/lib/rails/observers/action_controller/caching/sweeping.rb:73:in `around' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:455:in `public_send' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:455:in `block in make_lambda' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:312:in `block in halting' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:497:in `block in around' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:505:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:498:in `block (2 levels) in around' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:313:in `block (2 levels) in halting' | /usr/share/foreman/app/controllers/concerns/application_shared.rb:14:in `set_timezone' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:432:in `block in make_lambda' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:312:in `block in halting' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:497:in `block in around' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:505:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:498:in `block (2 levels) in around' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:313:in `block (2 levels) in halting' | /usr/share/foreman/app/models/concerns/foreman/thread_session.rb:32:in `clear_thread' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:432:in `block in make_lambda' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:312:in `block in halting' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:497:in `block in around' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:505:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:498:in `block (2 levels) in around' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:313:in `block (2 levels) in halting' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/rails-observers-0.1.2/lib/rails/observers/action_controller/caching/sweeping.rb:73:in `around' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:455:in `public_send' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:455:in `block in make_lambda' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:312:in `block in halting' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:497:in `block in around' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:505:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:92:in `__run_callbacks__' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:778:in `_run_process_action_callbacks' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:81:in `run_callbacks' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/abstract_controller/callbacks.rb:19:in `process_action' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_controller/metal/rescue.rb:29:in `process_action' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_controller/metal/instrumentation.rb:32:in `block in process_action' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/notifications.rb:164:in `block in instrument' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/notifications/instrumenter.rb:20:in `instrument' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/notifications.rb:164:in `instrument' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_controller/metal/instrumentation.rb:30:in `process_action' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_controller/metal/params_wrapper.rb:250:in `process_action' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activerecord-4.2.7.1/lib/active_record/railties/controller_runtime.rb:18:in `process_action' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/abstract_controller/base.rb:137:in `process' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionview-4.2.7.1/lib/action_view/rendering.rb:30:in `process' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_controller/metal.rb:196:in `dispatch' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_controller/metal/rack_delegation.rb:13:in `dispatch' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_controller/metal.rb:237:in `block in action' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/routing/route_set.rb:74:in `dispatch' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/routing/route_set.rb:43:in `serve' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/journey/router.rb:43:in `block in serve' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/journey/router.rb:30:in `each' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/journey/router.rb:30:in `serve' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/routing/route_set.rb:817:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/apipie-rails-0.3.7/lib/apipie/static_dispatcher.rb:65:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/apipie-rails-0.3.7/lib/apipie/extractor/recorder.rb:132:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/apipie-rails-0.3.7/lib/apipie/middleware/checksum_in_headers.rb:27:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/rack-1.6.5/lib/rack/etag.rb:24:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/rack-1.6.5/lib/rack/conditionalget.rb:38:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/rack-1.6.5/lib/rack/head.rb:13:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/middleware/params_parser.rb:27:in `call' | /usr/share/foreman/lib/middleware/catch_json_parse_errors.rb:8:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/middleware/flash.rb:260:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/rack-1.6.5/lib/rack/session/abstract/id.rb:225:in `context' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/rack-1.6.5/lib/rack/session/abstract/id.rb:220:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/middleware/cookies.rb:560:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activerecord-4.2.7.1/lib/active_record/query_cache.rb:36:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activerecord-4.2.7.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:653:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/middleware/callbacks.rb:29:in `block in call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:88:in `__run_callbacks__' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:778:in `_run_call_callbacks' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/callbacks.rb:81:in `run_callbacks' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/middleware/callbacks.rb:27:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/middleware/remote_ip.rb:78:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/middleware/show_exceptions.rb:30:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/railties-4.2.7.1/lib/rails/rack/logger.rb:38:in `call_app' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/railties-4.2.7.1/lib/rails/rack/logger.rb:22:in `call' | /usr/share/foreman/lib/middleware/tagged_logging.rb:18:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/middleware/request_id.rb:21:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/rack-1.6.5/lib/rack/methodoverride.rb:22:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/rack-1.6.5/lib/rack/runtime.rb:18:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/actionpack-4.2.7.1/lib/action_dispatch/middleware/static.rb:120:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/rack-1.6.5/lib/rack/sendfile.rb:113:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/secure_headers-3.6.1/lib/secure_headers/middleware.rb:12:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/railties-4.2.7.1/lib/rails/engine.rb:518:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/railties-4.2.7.1/lib/rails/application.rb:165:in `call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/railties-4.2.7.1/lib/rails/railtie.rb:194:in `public_send' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/railties-4.2.7.1/lib/rails/railtie.rb:194:in `method_missing' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/rack-1.6.5/lib/rack/urlmap.rb:66:in `block in call' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/rack-1.6.5/lib/rack/urlmap.rb:50:in `each' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/rack-1.6.5/lib/rack/urlmap.rb:50:in `call' | /usr/lib/ruby/vendor_ruby/phusion_passenger/rack/thread_handler_extension.rb:97:in `process_request' | /usr/lib/ruby/vendor_ruby/phusion_passenger/request_handler/thread_handler.rb:160:in `accept_and_process_next_request' | /usr/lib/ruby/vendor_ruby/phusion_passenger/request_handler/thread_handler.rb:113:in `main_loop' | /usr/lib/ruby/vendor_ruby/phusion_passenger/request_handler.rb:416:in `block (3 levels) in start_threads' | /usr/lib/ruby/vendor_ruby/phusion_passenger/utils.rb:113:in `block in create_thread_and_abort_on_exception' | /usr/share/foreman/vendor/cache/ruby/2.3.0/gems/logging-2.1.0/lib/logging/diagnostic_context.rb:450:in `block in create_with_logging_context'
2017-03-14T10:29:03 d45e6a3f [app] [I] Rendered common/500.html.erb within layouts/application (4.6ms)
2017-03-14T10:29:03 d45e6a3f [app] [I] Rendered layouts/_application_content.html.erb (0.4ms)
2017-03-14T10:29:03 d45e6a3f [app] [I] Rendered layouts/base.html.erb (2.9ms)
2017-03-14T10:29:03 d45e6a3f [app] [I] Completed 500 Internal Server Error in 113ms (Views: 10.2ms | ActiveRecord: 7.3ms)
2017-03-14T10:29:03 03a66c9f [app] [I] Started GET "/javascripts/locale/en/app.js" for 10.140.102.1 at 2017-03-14 10:29:03 +0100
2017-03-14T10:29:03 03a66c9f [app] [F] | ActionController::RoutingError (No route matches [GET] "/javascripts/locale/en/app.js"): | lib/middleware/tagged_logging.rb:18:in `call'