NoMethodError in AdminController#save_tasks

on saving a change in the global permissions the following error occured:

NoMethodError in AdminController#save_tasks

You have a nil object when you didn't expect it!
You might have expected an instance of ActiveRecord::Base.
The error occurred while evaluating nil.[]
RAILS_ROOT: /usr/local/wagn

Application Trace | Framework Trace | Full Trace
/usr/local/wagn/app/controllers/admin_controller.rb:39:in `save_tasks'
/usr/local/wagn/app/controllers/admin_controller.rb:38:in `each'
/usr/local/wagn/app/controllers/admin_controller.rb:38:in `save_tasks'
/var/lib/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:1331:in `send'
/var/lib/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:1331:in `perform_action_without_filters'
/var/lib/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/filters.rb:617:in `call_filters'
/var/lib/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/filters.rb:610:in `perform_action_without_benchmark'
/var/lib/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:68:in `perform_action_without_rescue'
/var/lib/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in `ms'
/var/lib/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in `ms'
/var/lib/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:68:in `perform_action_without_rescue'
/var/lib/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/rescue.rb:160:in `perform_action_without_flash'
/var/lib/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/flash.rb:146:in `perform_action'
/var/lib/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:532:in `send'
/var/lib/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:532:in `process_without_filters'
/var/lib/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/filters.rb:606:in `process'
/var/lib/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:391:in `process'
/var/lib/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:386:in `call'
/var/lib/gems/1.8/gems/actionpack-2.3.5/lib/action_controller/routing/route_set.rb:437:in `call'
Request

Parameters:

{"commit"=>"Save changes"}
Show session dump

Response

Headers:

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