Redmine

Did you follow the installation instruction? It seems that you have a problem with the assets compilation, you can try rebuild them:

6. Compile assets (optional)

Compile the assets such as stylesheets, javascripts and images into the public/assets
directory for web server delivery.

By default, Redmine automatically recompiles assets in production mode when the application starts.
This behavior can be controlled using the "config.assets.redmine_detect_update" flag in the configuration file.

To manually compile assets or if automatic compilation is disabled:

using:
bundle exec rake assets:precompile RAILS_ENV="production"

If deploying to a sub-uri, set the relative URL root as follows:
bundle exec rake assets:precompile RAILS_ENV="production" RAILS_RELATIVE_URL_ROOT=/sub-uri

If you experience issues with missing assets in the browser, try
removing the public/assets directory before re-running the precompile:
bundle exec rake assets:clobber RAILS_ENV="production"