Redmine

GET http://172.172.174.100/redmine/custom_fields.xml

- requests a username and password, I enter it (valid administrator credentials), but the authentication fails, the request returns nothing in the log

Started GET "/redmine/custom_fields.xml" for 172.172.174.100 at 2017-03-01 17:52:28 +0300
Processing by CustomFieldsController#index as XML
Current user: anonymous
Filter chain halted as :check_if_login_required rendered or redirected
Completed 401 Unauthorized in 45ms (ActiveRecord: 41.0ms)

Redmine info:

Environment:
Redmine version 3.3.1.stable
Ruby version 2.1.10-p492 (2016-04-01) [x86_64-linux]
Rails version 4.2.7.1
Environment production
Database adapter Mysql2
SCM:
Subversion 1.7.19
Git 2.7.4
Filesystem
Redmine plugins:
a_common_libs 2.2.3
aims 0.0.1
extra_queries 2.2.4
recurring_tasks 2.0.0-pre
redmine_activity_im_notificator 0.0.1
redmine_contacts 4.0.1
redmine_custom_workflows 0.1.6
redmine_default_custom_query 1.2.0
redmine_editauthor 0.9.1
redmine_issue_buttons 1.0.0
redmine_issue_tabs 1.1.1
redmine_subtasks_inherited_fields 1.1.0
redmine_theme_changer 0.2.0
subtask_list_columns 0.0.3
under_construction 2.0.2
usability 2.1.5