Conflict with Usability plugin (RM+)

[skillvrn]

Does not work with the module Usability (from developers RM+ http://rmplus.pro/ru/redmine/plugins/usability).
When disable usability module, then all is well.

Log:

Started POST "/projects/vrn/issues" for 10.1.100.5 at 2019-06-07 08:56:40 +0300
Processing by IssuesController#create as JSON
  Parameters: {"utf8"=>"✓", "project_id"=>"vrn"}
  Current user: sk (id=5)
  Rendered common/error_messages.api.rsb (20.3ms)
Completed 500 Internal Server Error in 517ms (ActiveRecord: 92.4ms)

ActionView::Template::Error (No builder for format ):
    1: api.array :errors do
    2:   @error_messages.each do |message|
    3:     api.error message
    4:   end
  lib/redmine/views/builders.rb:28:in `for'
  app/views/common/error_messages.api.rsb:1:in `_app_views_common_error_messages_api_rsb___4154218696316974310_70073216235480'
  app/controllers/application_controller.rb:671:in `render_api_errors'
  app/controllers/application_controller.rb:666:in `render_validation_errors'
  app/controllers/issues_controller.rb:150:in `block (2 levels) in create'
  app/controllers/issues_controller.rb:142:in `create'
  plugins/usability/lib/usability/issues_controller_patch.rb:42:in `create_with_usability'
  lib/redmine/sudo_mode.rb:63:in `sudo_mode'

Versions:

Environment:
  Redmine version                3.4.7.stable
  Ruby version                   2.4.5-p335 (2018-10-18) [x86_64-linux]
  Rails version                  4.2.11
  Environment                    production
  Database adapter               Mysql2
SCM:
  Git                            2.11.0
  Filesystem                     
Redmine plugins:
  a_common_libs                  2.5.3
  custom_menu                    1.8.5
  extra_queries                  2.3.5
  global_roles                   2.2.4
  redmine_checklists             3.1.14
  redmine_issue_dynamic_edit     0.6.7
  redmine_issue_tabs             1.3.1
  redmine_people                 1.4.0
  redmine_preview_docx           1.0.0
  redmine_thumbnail_pdf          1.0.4
  redmine_xlsx_format_issue_exporter 0.1.6
  rm_user_mentions               1.0.3
  rmplus_devtools                1.1.0
  under_construction             2.0.7
  unread_issues                  2.2.2
  usability                      2.3.8

[skillvrn]

The problem is still actual...