Redmine

Redmine 4.0 does not officially support Ruby 2.7. Also Redmine 4.0.x does not receive any updates and is not supported by the Redmine project anymore. You should update Redmine to a newer version.

With that being said, Redmine does not usually freeze any string, specifically not in the code path you have shown. Thus, this is likely to only occur if you force Ruby to create frozen strings by default (which will break a lot of areas in Redmine) by e.g. using RUBYOPT="--enable-frozen-string-literal" or similar. You should remove any such environment variables and configure your application server to not configure Ruby with frozen strings.

thank you for your answer,

i upgrade redmine debian package v4.0 to v5.0.x

But now i have 500 error :

Processing by WelcomeController#index as HTML
  Current user: alexandre (id=1)
  Rendering welcome/index.html.erb within layouts/base
  Rendered welcome/index.html.erb within layouts/base (33.8ms)
Completed 500 Internal Server Error in 132ms (ActiveRecord: 15.4ms)

ActionView::Template::Error (undefined method `atom_key' for #<User:0x0000555bd4ac6db0>
Did you mean?  to_key):
    21: </div>
    22: 
    23: <% content_for :header_tags do %>
    24: <%= auto_discovery_link_tag(:atom, {:controller => 'news', :action => 'index', :key => User.current.atom_key, :format => 'atom'},
    25:                                    :title => "#{Setting.app_title}: #{l(:label_news_latest)}") %>
    26: <%= auto_discovery_link_tag(:atom, {:controller => 'activities', :action => 'index', :key => User.current.atom_key, :format => 'atom'},
    27:                                    :title => "#{Setting.app_title}: #{l(:label_activity)}") %>

app/views/welcome/index.html.erb:24:in `block in _app_views_welcome_index_html_erb__4256216469183124722_73320'
app/views/welcome/index.html.erb:23:in `_app_views_welcome_index_html_erb__4256216469183124722_73320'
lib/redmine/sudo_mode.rb:63:in `sudo_mode'

Forgot to do something ?

bundle exec rake db:migrate RAILS_ENV=production  
rake aborted!
NoMethodError: undefined method `assets' for #<Rails::Application::Configuration:0x0000565003c055b8>
Did you mean?  asset_host
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/railtie/configuration.rb:97:in `method_missing'
/usr/share/redmine/config/initializers/assets.rb:4:in `<top (required)>'
/var/lib/gems/2.7.0/gems/activesupport-6.1.7.2/lib/active_support/dependencies.rb:326:in `load'
/var/lib/gems/2.7.0/gems/activesupport-6.1.7.2/lib/active_support/dependencies.rb:326:in `block in load'
/var/lib/gems/2.7.0/gems/activesupport-6.1.7.2/lib/active_support/dependencies.rb:299:in `load_dependency'
/var/lib/gems/2.7.0/gems/activesupport-6.1.7.2/lib/active_support/dependencies.rb:326:in `load'
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/engine.rb:681:in `block in load_config_initializer'
/var/lib/gems/2.7.0/gems/activesupport-6.1.7.2/lib/active_support/notifications.rb:205:in `instrument'
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/engine.rb:680:in `load_config_initializer'
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/engine.rb:634:in `block (2 levels) in <class:Engine>'
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/engine.rb:633:in `each'
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/engine.rb:633:in `block in <class:Engine>'
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/initializable.rb:32:in `instance_exec'
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/initializable.rb:32:in `run'
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/initializable.rb:61:in `block in run_initializers'
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/initializable.rb:50:in `each'
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/initializable.rb:50:in `tsort_each_child'
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/initializable.rb:60:in `run_initializers'
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/application.rb:391:in `initialize!'
/usr/share/redmine/config/environment.rb:16:in `<top (required)>'
/var/lib/gems/2.7.0/gems/zeitwerk-2.6.7/lib/zeitwerk/kernel.rb:38:in `require'
/var/lib/gems/2.7.0/gems/zeitwerk-2.6.7/lib/zeitwerk/kernel.rb:38:in `require'
/var/lib/gems/2.7.0/gems/activesupport-6.1.7.2/lib/active_support/dependencies.rb:332:in `block in require'
/var/lib/gems/2.7.0/gems/activesupport-6.1.7.2/lib/active_support/dependencies.rb:299:in `load_dependency'
/var/lib/gems/2.7.0/gems/activesupport-6.1.7.2/lib/active_support/dependencies.rb:332:in `require'
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/application.rb:367:in `require_environment!'
/var/lib/gems/2.7.0/gems/railties-6.1.7.2/lib/rails/application.rb:533:in `block in run_tasks_blocks'
/var/lib/gems/2.7.0/gems/rake-13.0.6/exe/rake:27:in `<top (required)>'
Tasks: TOP => db:migrate => db:load_config => environment
(See full trace by running task with --trace)

Thank you