Redmine

New Debian System - Redmine SQL data migrated from 5.x.

It does not matter whether the user is root:root or www-data:www-data. The rights of the directory are 755
The error is always the same:

App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] Started GET "/settings" for xxxx::yyyy at 2025-02-07 09:48:59 +0000
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] Processing by SettingsController#index as HTML
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973]   Current user: admin (id=1)
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973]   Rendered layout layouts/admin.html.erb (Duration: 8.5ms | GC: 0.0ms)
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] Completed 500 Internal Server Error in 32ms (ActiveRecord: 2.5ms (5 queries, 0 cached) | GC: 0.0ms)
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973]   
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] ActionView::Template::Error (Permission denied @ dir_s_mkdir - /var/www/redmine-6.0/tmp/cache/E6B):
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] 
App 2063 output: Causes:
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] Errno::EACCES (Permission denied @ dir_s_mkdir - /var/www/redmine-6.0/tmp/cache/E6B)
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973]     3: <div class="box tabular settings">
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973]     4: <p><%= setting_select :ui_theme, Redmine::Themes.themes.collect {|t| [t.name, t.id]}, :blank => :label_default, :label => :label_theme %></p>
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973]     5: 
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973]     6: <p><%= setting_select :default_language, lang_options_for_select(false) %></p>
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973]     7: 
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973]     8: <p><%= setting_check_box :force_default_language_for_anonymous %></p>
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973]     9: 
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973]   
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] lib/redmine/i18n.rb:151:in `languages_options'
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] app/helpers/application_helper.rb:1534:in `lang_options_for_select'
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] app/views/settings/_display.html.erb:6
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] app/views/settings/_display.html.erb:1
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] app/views/common/_tabs.html.erb:21
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] app/views/common/_tabs.html.erb:20:in `each'
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] app/views/common/_tabs.html.erb:20
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] app/helpers/application_helper.rb:526:in `render_tabs'
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] app/views/settings/edit.html.erb:5
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] app/controllers/settings_controller.rb:33:in `index'
App 2063 output: [f1f4565e-4b7d-49fd-81d8-e38392985973] lib/redmine/sudo_mode.rb:78:in `sudo_mode'

Any hints for me