# Can't seem to instantiate Builder::XmlMarkup.new?

**URL:** <https://www.ruby-forum.com/t/cant-seem-to-instantiate-builder-xmlmarkup-new/160792>\
**Category:** Rails\
**Created:** [February 19, 2009, 6:48pm UTC](https://www.ruby-forum.com/t/cant-seem-to-instantiate-builder-xmlmarkup-new/160792 "2009-02-19T18:48:12Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![InventoryTrackers](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/59ef9b/32.png) [@InventoryTrackers](https://www.ruby-forum.com/u/InventoryTrackers)\
**Post date:** [February 19, 2009, 6:48pm UTC](https://www.ruby-forum.com/t/cant-seem-to-instantiate-builder-xmlmarkup-new/160792/1 "2009-02-19T18:48:12Z")

</div>

I am unable to instantiate the Builder::XmlMarkup.new on one  
development machine ( Windows ) and upon my CentOS server. When I run  
the same code on my Ubuntu 8.10 VMWare machine, everything runs great?

In the Builder documentation ( [http://builder.rubyforge.org/](http://builder.rubyforge.org/) ) it  
shows to put this at the top of the controller;

require ‘rubygems’  
require\_gem ‘builder’

but this causes the controller to fail when it opens. I’ve locally  
installed the ‘Builder’ gem although this doesn’t exist in my Linux  
stack and runs fine. Here’s the details on the GEM I installed;  
gem = “Builder” by removed\_email\_address@domain.invalid at [http://onestepback.org/](http://onestepback.org/)

Does ActiveRecord ( as of 2.2.2 ) now have this feature? If so, why  
can’t my controller create an instance of this class?

David