NoMethodError in Student#solicitud_beca

Showing app/views/layouts/application.html.erb where line #55 raised:

undefined method `gsub' for nil:NilClass

Extracted source (around line #55):

52:         <div id="outer-header-link">
53:           <div id="header_link" >
54:             <% @an = session[:anyo] %>
55: 		   Año Académico: <%= link_to @an.gsub(/.{4}(?=.)/, '\0/'),{:controller=>"user", :action=>"cambio_ano"}%> &nbsp;|&nbsp;
56:             Registrado como: 
57:             <%= link_to @user.first_name, :controller => 'user', :action => 'profile',
58:               :id => @user.username %> &nbsp;|&nbsp;

RAILS_ROOT: /home/institut/ruby/gestor

Application Trace | Framework Trace | Full Trace
/home/institut/ruby/gestor/app/views/layouts/application.html.erb:55:in `_run_erb_app47views47layouts47application46html46erb'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_view/renderable.rb:34:in `block in render'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_view/base.rb:307:in `with_template'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_view/renderable.rb:30:in `render'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_view/template.rb:206:in `render_template'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_view/base.rb:266:in `render'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_view/base.rb:353:in `_render_with_layout'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_view/base.rb:263:in `render'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/base.rb:1253:in `render_for_file'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/base.rb:937:in `render'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/benchmarking.rb:52:in `block in render_with_benchmark'
/home/institut/ruby/gems/gems/activesupport-2.3.15/lib/active_support/core_ext/benchmark.rb:18:in `block in ms'
/opt/ruby-lur/lib/ruby/1.9.1/benchmark.rb:295:in `realtime'
/home/institut/ruby/gems/gems/activesupport-2.3.15/lib/active_support/core_ext/benchmark.rb:18:in `ms'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/benchmarking.rb:52:in `render_with_benchmark'
/home/institut/ruby/gestor/vendor/plugins/wicked_pdf/lib/pdf_helper.rb:20:in `render_with_wicked_pdf'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/base.rb:1329:in `default_render'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/base.rb:1335:in `perform_action'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/filters.rb:618:in `call_filters'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/filters.rb:611:in `perform_action_with_filters'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/benchmarking.rb:69:in `block in perform_action_with_benchmark'
/home/institut/ruby/gems/gems/activesupport-2.3.15/lib/active_support/core_ext/benchmark.rb:18:in `block in ms'
/opt/ruby-lur/lib/ruby/1.9.1/benchmark.rb:295:in `realtime'
/home/institut/ruby/gems/gems/activesupport-2.3.15/lib/active_support/core_ext/benchmark.rb:18:in `ms'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/benchmarking.rb:69:in `perform_action_with_benchmark'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/rescue.rb:161:in `perform_action_with_rescue'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/flash.rb:152:in `perform_action_with_flash'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/base.rb:533:in `process'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/filters.rb:607:in `process_with_filters'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/base.rb:392:in `process'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/base.rb:387:in `call'
/home/institut/ruby/gems/gems/actionpack-2.3.15/lib/action_controller/routing/route_set.rb:439:in `call'

Request

Parameters:

None

Show session dump

Response

Headers:

{"Cache-Control"=>"no-cache",
 "Content-Type"=>"text/html"}