I am getting errors when run these commands

XXXXXXXXXX:~/.coupa-1.5#gem list
*** LOCAL GEMS ***

actionmailer (2.3.8)
actionpack (2.3.8)
activerecord (2.3.8)
activeresource (2.3.8)
activesupport (2.3.8)
acts_as_ferret (0.4.1)
daemons (1.0.10)
gem_plugin (0.2.3)
gemsonrails (0.7.2)
minitest (1.6.0)
mongrel (1.2.0.pre2)
mysql (2.8.1)
rack (1.1.0)
rails (2.3.8)
rake (0.8.7)
rdoc (2.5.8)
rtf (0.1.0)
rubygems-update (1.3.7)
rvm (0.1.45)
sdsykes-ferret (0.11.6.19)
test-unit (2.1.1)
vpim (0.695)

XXXXXXXXX:~/.coupa-1.5# mongrel_rails start
** Starting Mongrel listening at 0.0.0.0:3000
** Starting Rails with development environment…
Your config/boot.rb is outdated: Run “rake rails:update”.

XXXXXXXXX:~/.coupa-1.5# rake rails:update
(in /root/.coupa-1.5)
DEPRECATION WARNING: Rake tasks in vendor/plugins/backgroundrb/tasks,
vendor/plugins/blueprint/tasks, vendor/plugins/coupa_engine/tasks,
vendor/plugins/deprecated/tasks, vendor/plugins/engines/tasks, vendor/
plugins/human_attribute_override/tasks, vendor/plugins/scoped_access/
tasks, vendor/plugins/selenium-on-rails/tasks, and vendor/plugins/
user_engine/tasks are deprecated. Use lib/tasks instead. (called from
<top (required)> at /usr/local/lib/ruby/gems/1.9.1/gems/rails-2.3.8/
lib/tasks/rails.rb:10)
rake aborted!
no such file to load – yaml/encoding
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.8/lib/
active_support/dependencies.rb:156:in require' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.8/lib/ active_support/dependencies.rb:156:inblock in require’
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.8/lib/
active_support/dependencies.rb:521:in new_constants_in' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.8/lib/ active_support/dependencies.rb:156:inrequire’
/root/.coupa-1.5/vendor/plugins/coupa_engine/tasks/coupa_engine.rake:
31:in block (2 levels) in <top (required)>' /usr/local/lib/ruby/1.9.1/rake.rb:1874:inin_namespace’
/usr/local/lib/ruby/1.9.1/rake.rb:908:in namespace' /root/.coupa-1.5/vendor/plugins/coupa_engine/tasks/coupa_engine.rake: 21:inblock in <top (required)>’
/usr/local/lib/ruby/1.9.1/rake.rb:1874:in in_namespace' /usr/local/lib/ruby/1.9.1/rake.rb:908:innamespace’
/root/.coupa-1.5/vendor/plugins/coupa_engine/tasks/coupa_engine.rake:
17:in <top (required)>' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.8/lib/ active_support/dependencies.rb:145:inload’
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.8/lib/
active_support/dependencies.rb:145:in block in load_with_new_constant_marking' /usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.8/lib/ active_support/dependencies.rb:521:innew_constants_in’
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-2.3.8/lib/
active_support/dependencies.rb:145:in load_with_new_constant_marking' /usr/local/lib/ruby/gems/1.9.1/gems/rails-2.3.8/lib/tasks/rails.rb: 11:inblock in <top (required)>’
/usr/local/lib/ruby/gems/1.9.1/gems/rails-2.3.8/lib/tasks/rails.rb:
11:in each' /usr/local/lib/ruby/gems/1.9.1/gems/rails-2.3.8/lib/tasks/rails.rb: 11:in<top (required)>’
/root/.coupa-1.5/Rakefile.rb:10:in require' /root/.coupa-1.5/Rakefile.rb:10:in<top (required)>’
/usr/local/lib/ruby/1.9.1/rake.rb:2373:in load' /usr/local/lib/ruby/1.9.1/rake.rb:2373:inraw_load_rakefile’
/usr/local/lib/ruby/1.9.1/rake.rb:2007:in block in load_rakefile' /usr/local/lib/ruby/1.9.1/rake.rb:2058:instandard_exception_handling’
/usr/local/lib/ruby/1.9.1/rake.rb:2006:in load_rakefile' /usr/local/lib/ruby/1.9.1/rake.rb:1991:inrun’
/usr/local/bin/rake:31:in `’

if i run any rake command i get same
errors…