uninitialized class variable @@env in OCI8

Can anyone help me with the uninitialized class variable @@env in OCI8
error raised in my app\views\xxxx index.html.erb file

Thanks in advance

Below is the code and the result of bundle show. I am using Windows 7

<h1>Listing comics</h1>

<table>
  <tr>
    <th>Title</th>
    <th>Issue</th>
    <th>Publisher</th>
    <th></th>
    <th></th>
    <th></th>
  </tr>

<% @comics.each do |comic| %>
  <tr>
    <td><%= comic.title %></td>
    <td><%= comic.issue %></td>
    <td><%= comic.publisher %></td>
    <td><%= link_to 'Show', comic %></td>
    <td><%= link_to 'Edit', edit_comic_path(comic) %></td>
    <td><%= link_to 'Destroy', comic, :confirm => 'Are you
sure?', :method => :delete %></td>
  </tr>
<% end %>
</table>

Gems included by the bundle
  * abstract (1.0.0)
  * actionmailer (3.0.8)
  * actionpack (3.0.8)
  * activemodel (3.0.8)
  * activerecord (3.0.8)
  * activeresource (3.0.8)
  * activesupport (3.0.8)
  * arel (2.0.10)
  * builder (2.1.2)
  * bundler (1.0.15)
  * erubis (2.6.6)
  * i18n (0.5.0)
  * mail (2.2.19)
  * mime-types (1.16)
  * polyglot (0.3.1)
  * rack (1.2.3)
  * rack-mount (0.6.14)
  * rack-test (0.5.7)
  * rails (3.0.8)
  * railties (3.0.8)
  * rake (0.9.2)
  * ruby-oci8 (2.0.6)
  * thor (0.14.6)
  * treetop (1.4.9)
  * tzinfo (0.3.28)