# Launch error

**URL:** <https://www.ruby-forum.com/t/launch-error/189730>\
**Category:** Rails\
**Created:** [June 6, 2010, 12:10pm UTC](https://www.ruby-forum.com/t/launch-error/189730 "2010-06-06T12:10:27Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![mperham](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e47c2d/32.png) [@mperham](https://www.ruby-forum.com/u/mperham)\
**Post date:** [June 6, 2010, 12:10pm UTC](https://www.ruby-forum.com/t/launch-error/189730/1 "2010-06-06T12:10:27Z")

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Hey all, I am just getting started with RoR and am having trouble  
launching the localhost:3000 page. Here is the error message I am  
getting in my command prompt:

`C:\Users\Michael\rubydev\ch04\first>ruby script/server
C:/Ruby19/lib/ruby/site_ruby/1.9.1/rubygems.rb:827:in
report_activate_error': R ubyGem version error: rack(1.0.0 not ~> 1.0.1) (Gem::LoadError) from C:/Ruby19/lib/ruby/site_ruby/1.9.1/rubygems.rb:261:inactivate’
from C:/Ruby19/lib/ruby/site_ruby/1.9.1/rubygems.rb:68:in gem' from C:/Ruby19/lib/ruby/gems/1.9.1/gems/actionpack-2.3.5/lib/action_cont roller.rb:34:in<top (required)>’
from
C:/Ruby19/lib/ruby/gems/1.9.1/gems/activesupport-2.3.5/lib/active_s
upport/dependencies.rb:156:in require' from C:/Ruby19/lib/ruby/gems/1.9.1/gems/activesupport-2.3.5/lib/active_s upport/dependencies.rb:156:inblock in require’
from
C:/Ruby19/lib/ruby/gems/1.9.1/gems/activesupport-2.3.5/lib/active_s
upport/dependencies.rb:521:in new_constants_in' from C:/Ruby19/lib/ruby/gems/1.9.1/gems/activesupport-2.3.5/lib/active_s upport/dependencies.rb:156:inrequire’
from
C:/Ruby19/lib/ruby/gems/1.9.1/gems/rails-2.3.5/lib/commands/server.
rb:2:in <top (required)>' from script/server:3:inrequire’
from script/server:3:in `’ `

I am not sure how to fix this, any advice would be great! thank you in  
advance!

---

<div class="post-metadata">

**Author:** ![mperham](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e47c2d/32.png) [@mperham](https://www.ruby-forum.com/u/mperham)\
**Post date:** [June 8, 2010, 9:43pm UTC](https://www.ruby-forum.com/t/launch-error/189730/2 "2010-06-08T21:43:22Z")

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On Jun 6, 6:10 am, Mike P. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> ```
> from C:/Ruby19/lib/ruby/site_ruby/1.9.1/rubygems.rb:68:in `gem'
> 
> ```
> 
> ## C:/Ruby19/lib/ruby/gems/1.9.1/gems/activesupport-2.3.5/lib/active\_s I am not sure how to fix this, any advice would be great! thank you in advance!
> 
> Posted viahttp://www.ruby-forum.com/.

Hi Mike,

I got a similar error to this before.This happened when I was  
tinkering with the environment.rb. If you’ve done this, you’ll want to  
revert everything back.

I haven’t found a solution to fix this, so the best advice I can give  
you is download Ruby 1.8.7 and redo the whole installation process as  
well as your coding. You’ll want to work in the Ruby 1.8.7 terminal so  
the computer won’t get confused about which Ruby version you’re using.  
It’s not the best solution and far from ideal, but it’s the only one I  
have.

Wish you luck 🙂  
Anon\_comp

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<div class="post-metadata">

**Author:** ![mperham](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e47c2d/32.png) [@mperham](https://www.ruby-forum.com/u/mperham)\
**Post date:** [June 8, 2010, 11:34pm UTC](https://www.ruby-forum.com/t/launch-error/189730/3 "2010-06-08T23:34:01Z")

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Do you have the rack -v 1.0.1 gem installed?