# Installing problem

**URL:** <https://www.ruby-forum.com/t/installing-problem/135814>\
**Category:** Engines\
**Created:** [April 25, 2008, 8:42am UTC](https://www.ruby-forum.com/t/installing-problem/135814 "2008-04-25T08:42:00Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![zemariamm](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/58956e/32.png) [@zemariamm](https://www.ruby-forum.com/u/zemariamm)\
**Post date:** [April 25, 2008, 8:42am UTC](https://www.ruby-forum.com/t/installing-problem/135814/1 "2008-04-25T08:42:00Z")

</div>

Hello guys,  
I’ve used rails engines in the past, but now I was configuring a new  
system and I can’t get the engines to work, when I try to generate the  
migrations for the plugins with the command:  
ruby script/generate plugin\_migration I have the following error:

clustermedia-labss-macbook-pro:teste we$ ruby script/generate  
plugin\_migration  
/Library/Ruby/Gems/1.8/gems/activesupport-1.4.2/lib/active\_support/dependencies.rb:263:in  
`load_missing_constant': uninitialized constant Rails::Plugin (NameError) from /Library/Ruby/Gems/1.8/gems/activesupport-1.4.2/lib/active_support/dependencies.rb:452:in`const\_missing’  
from  
./script/…/config/…/vendor/plugins/engines/lib/engines/plugin.rb:15  
from  
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/custom\_require.rb:27:in  
`gem_original_require' from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/custom_require.rb:27:in`require’  
from  
/Library/Ruby/Gems/1.8/gems/activesupport-1.4.2/lib/active\_support/dependencies.rb:495:in  
`require' from /Library/Ruby/Gems/1.8/gems/activesupport-1.4.2/lib/active_support/dependencies.rb:342:in`new\_constants\_in’  
from  
/Library/Ruby/Gems/1.8/gems/activesupport-1.4.2/lib/active\_support/dependencies.rb:495:in  
`require' from ./script/../config/../vendor/plugins/engines/lib/engines.rb:2 ... 25 levels... from /Library/Ruby/Gems/1.8/gems/rails-1.2.3/lib/commands/generate.rb:1 from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/custom_require.rb:27:in`gem\_original\_require’  
from  
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/custom\_require.rb:27:in  
`require’  
from script/generate:3

I’ve tried with many many differente rails versions (from 1.1.6 to  
1.2.5) and I always get this error… any ideas ?

tks,  
Ze Maria