attr_accessible error on rails 4.1.8 upon performing rake db:migrate on heroku

I am still learning Ruby (so I am a complete noob), right now I have my app successfully running locally but when trying to opening the apps on heroku , in which I first perform the heroku run rake db:migrate I stumbled upon a problem.. it tells me :

Running `rake db:migrate` attached to terminal... up, run.2149
-- attr_accessible(:pName, :pQuantity, :pMeter, :pWeight, :pSellPrice,  :pCategory, :pPic)
-- attr_accessible(:pName, :pQuantity, :pMeter, :pWeight, :pSellPrice, :pCategory, :pPic)
rake aborted!
NoMethodError: undefined method `attr_accessible' for #<ActiveRecord::Migration:0x007f2dc2ba45b8>
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:648:in `block in method_missing'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:621:in `block in say_with_time'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:621:in `say_with_time'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:641:in `method_missing'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:406:in `method_missing'
/app/db/migrate/20150802134246_create_inventories.rb:2:in `<class:CreateInventories>'
/app/db/migrate/20150802134246_create_inventories.rb:1:in `<top (required)>'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:247:in `require'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:247:in `block in require'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:232:in `load_dependency'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/dependencies.rb:247:in `require'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:761:in `load_migration'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:757:in `migration'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:752:in `disable_ddl_transaction'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:1044:in `use_transaction?'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:954:in `rescue in block in migrate'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:951:in `block in migrate'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:948:in `each'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:948:in `migrate'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:807:in `up'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/migration.rb:785:in `migrate'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.8/lib/active_record/railties/databases.rake:34:in `block (2 levels) in <top (required)>'
Tasks: TOP => db:migrate

I have been trying to find out the reason, after wondering around I found out about change in rails 4.0.0 in that attr_accessible are no longer used and we should use strong parameter instead, So removing the attr_accessible from model will solve the problem...

However, I have an empty Model, there is no attr_accessible everywhere i look. (beside this is weird why my apps runs locally but not on heroku?) I can't figured out why this error appear and where to look for solutions.. I have been trying to look at active_record file but am afraid of making any changes, any idea?

also, could anyone tell me any resources that can help me read this type of log errors? I have tried to read some articles but can't find one that is easy to understand for noobs like me... ;(