Ruby (Rack) application could not be started

These are the possible causes:
  • There may be a syntax error in the application's code. Please check for such errors and fix them.
  • A required library may not installed. Please install all libraries that this application requires.
  • The application may not be properly configured. Please check whether all configuration files are written correctly, fix any incorrect configurations, and restart this application.
  • A service that the application relies on (such as the database server or the Ferret search engine server) may not have been started. Please start that service.
Further information about the error may have been written to the application's log file. Please check it in order to analyse the problem.
Error message:
No such file or directory - config.ru
Exception class:
Errno::ENOENT
Application root:
/home6/alexwith/public_html/domains
Backtrace:
# File Line Location
0 /etc/httpd/modules/passenger/lib/phusion_passenger/utils.rb 684 in `lstat'
1 /etc/httpd/modules/passenger/lib/phusion_passenger/utils.rb 684 in `lower_privilege'
2 /etc/httpd/modules/passenger/lib/phusion_passenger/utils.rb 198 in `prepare_app_process'
3 /etc/httpd/modules/passenger/lib/phusion_passenger/rack/application_spawner.rb 156 in `block in initialize_server'
4 /etc/httpd/modules/passenger/lib/phusion_passenger/utils.rb 572 in `report_app_init_status'
5 /etc/httpd/modules/passenger/lib/phusion_passenger/rack/application_spawner.rb 154 in `initialize_server'
6 /etc/httpd/modules/passenger/lib/phusion_passenger/abstract_server.rb 204 in `start_synchronously'
7 /etc/httpd/modules/passenger/lib/phusion_passenger/abstract_server.rb 180 in `start'
8 /etc/httpd/modules/passenger/lib/phusion_passenger/rack/application_spawner.rb 129 in `start'
9 /etc/httpd/modules/passenger/lib/phusion_passenger/spawn_manager.rb 253 in `block (2 levels) in spawn_rack_application'
10 /etc/httpd/modules/passenger/lib/phusion_passenger/abstract_server_collection.rb 132 in `lookup_or_add'
11 /etc/httpd/modules/passenger/lib/phusion_passenger/spawn_manager.rb 246 in `block in spawn_rack_application'
12 /etc/httpd/modules/passenger/lib/phusion_passenger/abstract_server_collection.rb 82 in `block in synchronize'
13 prelude> 10:in `synchronize'
14 /etc/httpd/modules/passenger/lib/phusion_passenger/abstract_server_collection.rb 79 in `synchronize'
15 /etc/httpd/modules/passenger/lib/phusion_passenger/spawn_manager.rb 244 in `spawn_rack_application'
16 /etc/httpd/modules/passenger/lib/phusion_passenger/spawn_manager.rb 137 in `spawn_application'
17 /etc/httpd/modules/passenger/lib/phusion_passenger/spawn_manager.rb 275 in `handle_spawn_application'
18 /etc/httpd/modules/passenger/lib/phusion_passenger/abstract_server.rb 357 in `server_main_loop'
19 /etc/httpd/modules/passenger/lib/phusion_passenger/abstract_server.rb 206 in `start_synchronously'
20 /etc/httpd/modules/passenger/helper-scripts/passenger-spawn-server 99 in `
'