Redmine

hi,

got error 500 on my redmine url

ip - - [11/Sep/2013:12:03:59 +0200] "GET / HTTP/1.1" 500 613 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:23.0) Gecko/20100101 Firefox/23.0"

nothing special in the log files

here my setup

RAILS_ENV=production script/about

Environment:
      Redmine version                2.3.2.stable
      Ruby version                   1.9.3-p448 (2013-06-27) [x86_64-linux]
      Rails version                  3.2.13
      Environment                    production
      Database adapter               Mysql2
    Redmine plugins:
      no plugin installed

gem list

*** LOCAL GEMS ***

abstract (1.0.0)
actionmailer (4.0.0, 3.2.14, 3.2.13)
actionpack (4.0.0, 3.2.14, 3.2.13)
activemodel (4.0.0, 3.2.14, 3.2.13)
activerecord (4.0.0, 3.2.14, 3.2.13)
activerecord-deprecated_finders (1.0.3)
activerecord-mysql-adapter (0.0.1)
activeresource (4.0.0, 3.2.14, 3.2.13)
activesupport (4.0.0, 3.2.14, 3.2.13)
arel (4.0.0, 3.0.2)
atomic (1.1.14)
bcrypt-ruby (3.1.2)
builder (3.2.2, 3.1.4, 3.0.4, 3.0.0)
bundle (0.0.1)
bundler (1.3.5)
capybara (2.0.3)
childprocess (0.3.9)
coderay (1.1.0, 1.0.9)
coffee-rails (4.0.0, 3.2.2)
coffee-script (2.2.0)
coffee-script-source (1.6.3)
daemon_controller (1.1.5)
erubis (2.7.0)
execjs (2.0.1)
ffi (1.9.0, 1.4.0)
hike (1.2.3)
i18n (0.6.5, 0.6.1)
journey (1.0.4)
jquery-rails (2.3.0, 2.0.3)
json (1.8.0)
listen (0.7.3)
mail (2.5.4)
metaclass (0.0.1)
mime-types (1.25, 1.23)
minitest (4.7.5)
mocha (0.13.3)
multi_json (1.8.0, 1.6.1)
mysql (2.9.1)
mysql2 (0.3.13)
net-ldap (0.3.1)
nokogiri (1.5.10)
passenger (4.0.17)
pg (0.16.0)
polyglot (0.3.3)
racc (1.4.9)
rack (1.5.2, 1.4.5)
rack-cache (1.2)
rack-openid (1.3.1)
rack-ssl (1.3.3)
rack-test (0.6.2)
rails (4.0.0, 3.2.14, 3.2.13)
rails-observers (0.1.2)
railties (4.0.0, 3.2.14, 3.2.13)
rake (10.1.0, 0.9.6)
rake-compiler (0.9.1)
rb-inotify (0.9.1)
rdoc (4.0.1, 3.12.2)
rmagick (2.13.2)
ruby-openid (2.1.8)
rubyzip (0.9.9)
sass (3.2.10)
sass-rails (3.2.6)
selenium-webdriver (2.35.1)
shoulda (3.3.2)
shoulda-context (1.0.2)
shoulda-matchers (1.4.1)
sprockets (2.10.0, 2.2.2)
sprockets-rails (2.0.0)
sqlite3 (1.3.8)
thor (0.18.1)
thread_safe (0.1.3)
tilt (1.4.1)
treetop (1.4.15)
tzinfo (1.0.1, 0.3.37)
uglifier (2.2.1)
websocket (1.0.7)
xpath (1.0.0)
yard (0.8.7)

My previous installation work fine with passenger.

What is the cause of an error 500 for redmines ?

thanks for your help