ruby on rails 3 - wrong number of arguments (0 for 1) upon adding an erb file for controller action -

i facing weird issue , unfortunately, rails doesn't provide useful stack traces debugging. have standard controller, posts_controller. in routes, have defined resources :posts.

i have implemented basic index action. if go .../posts, output "template missing" expected because haven't created index.html.erb file in views/posts directory.

however, after create blank index.html.erb file in directory, "wrong number of arguments (0 1)".

there no application trace.

the framework trace is:

actionpack (3.0.3) lib/action_controller/metal/rendering.rb:18:in `content_type' actionpack (3.0.3) lib/action_controller/metal/rendering.rb:18:in `render' actionpack (3.0.3) lib/action_controller/metal/instrumentation.rb:40:in `render' activesupport (3.0.3) lib/active_support/core_ext/benchmark.rb:5:in `ms' /system/library/frameworks/ruby.framework/versions/1.8/usr/lib/ruby/1.8/benchmark.rb:308:in `realtime' activesupport (3.0.3) lib/active_support/core_ext/benchmark.rb:5:in `ms' actionpack (3.0.3) lib/action_controller/metal/instrumentation.rb:40:in `render' actionpack (3.0.3) lib/action_controller/metal/instrumentation.rb:78:in `cleanup_view_runtime' activerecord (3.0.3) lib/active_record/railties/controller_runtime.rb:15:in `cleanup_view_runtime' actionpack (3.0.3) lib/action_controller/metal/instrumentation.rb:39:in `render' actionpack (3.0.3) lib/action_controller/metal/implicit_render.rb:10:in `default_render' actionpack (3.0.3) lib/action_controller/metal/implicit_render.rb:5:in `send_action' actionpack (3.0.3) lib/abstract_controller/base.rb:151:in `process_action' actionpack (3.0.3) lib/action_controller/metal/rendering.rb:11:in `process_action' actionpack (3.0.3) lib/abstract_controller/callbacks.rb:18:in `process_action' activesupport (3.0.3) lib/active_support/callbacks.rb:450:in `_run__84203013__process_action__199225275__callbacks' activesupport (3.0.3) lib/active_support/callbacks.rb:409:in `send' activesupport (3.0.3) lib/active_support/callbacks.rb:409:in `_run_process_action_callbacks' activesupport (3.0.3) lib/active_support/callbacks.rb:93:in `send' activesupport (3.0.3) lib/active_support/callbacks.rb:93:in `run_callbacks' actionpack (3.0.3) lib/abstract_controller/callbacks.rb:17:in `process_action' actionpack (3.0.3) lib/action_controller/metal/instrumentation.rb:30:in `process_action' activesupport (3.0.3) lib/active_support/notifications.rb:52:in `instrument' activesupport (3.0.3) lib/active_support/notifications/instrumenter.rb:21:in `instrument' activesupport (3.0.3) lib/active_support/notifications.rb:52:in `instrument' actionpack (3.0.3) lib/action_controller/metal/instrumentation.rb:29:in `process_action' actionpack (3.0.3) lib/action_controller/metal/rescue.rb:17:in `process_action' newrelic_rpm (2.13.4) lib/new_relic/agent/instrumentation/rails3/action_controller.rb:34:in `process_action' newrelic_rpm (2.13.4) lib/new_relic/agent/instrumentation/controller_instrumentation.rb:252:in `perform_action_with_newrelic_trace' newrelic_rpm (2.13.4) lib/new_relic/agent/method_tracer.rb:141:in `trace_execution_scoped' newrelic_rpm (2.13.4) lib/new_relic/agent/instrumentation/controller_instrumentation.rb:247:in `perform_action_with_newrelic_trace' newrelic_rpm (2.13.4) lib/new_relic/agent/instrumentation/rails3/action_controller.rb:33:in `process_action' actionpack (3.0.3) lib/abstract_controller/base.rb:120:in `process' actionpack (3.0.3) lib/abstract_controller/rendering.rb:40:in `process' actionpack (3.0.3) lib/action_controller/metal.rb:138:in `dispatch' actionpack (3.0.3) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch' actionpack (3.0.3) lib/action_controller/metal.rb:178:in `action' actionpack (3.0.3) lib/action_dispatch/routing/route_set.rb:62:in `call' actionpack (3.0.3) lib/action_dispatch/routing/route_set.rb:62:in `dispatch' actionpack (3.0.3) lib/action_dispatch/routing/route_set.rb:27:in `call' rack-mount (0.6.13) lib/rack/mount/route_set.rb:148:in `call' rack-mount (0.6.13) lib/rack/mount/code_generation.rb:93:in `recognize' rack-mount (0.6.13) lib/rack/mount/code_generation.rb:75:in `optimized_each' rack-mount (0.6.13) lib/rack/mount/code_generation.rb:92:in `recognize' rack-mount (0.6.13) lib/rack/mount/route_set.rb:139:in `call' actionpack (3.0.3) lib/action_dispatch/routing/route_set.rb:492:in `call' newrelic_rpm (2.13.4) lib/new_relic/rack/developer_mode.rb:20:in `call' actionpack (3.0.3) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call' actionpack (3.0.3) lib/action_dispatch/middleware/head.rb:14:in `call' rack (1.2.1) lib/rack/methodoverride.rb:24:in `call' actionpack (3.0.3) lib/action_dispatch/middleware/params_parser.rb:21:in `call' actionpack (3.0.3) lib/action_dispatch/middleware/flash.rb:182:in `call' actionpack (3.0.3) lib/action_dispatch/middleware/session/abstract_store.rb:149:in `call' actionpack (3.0.3) lib/action_dispatch/middleware/cookies.rb:295:in `call' activerecord (3.0.3) lib/active_record/query_cache.rb:32:in `call' activerecord (3.0.3) lib/active_record/connection_adapters/abstract/query_cache.rb:28:in `cache' activerecord (3.0.3) lib/active_record/query_cache.rb:12:in `cache' activerecord (3.0.3) lib/active_record/query_cache.rb:31:in `call' activerecord (3.0.3) lib/active_record/connection_adapters/abstract/connection_pool.rb:353:in `call' actionpack (3.0.3) lib/action_dispatch/middleware/callbacks.rb:46:in `call' activesupport (3.0.3) lib/active_support/callbacks.rb:415:in `_run_call_callbacks' actionpack (3.0.3) lib/action_dispatch/middleware/callbacks.rb:44:in `call' rack (1.2.1) lib/rack/sendfile.rb:107:in `call' actionpack (3.0.3) lib/action_dispatch/middleware/remote_ip.rb:48:in `call' actionpack (3.0.3) lib/action_dispatch/middleware/show_exceptions.rb:46:in `call' railties (3.0.3) lib/rails/rack/logger.rb:13:in `call' rack (1.2.1) lib/rack/runtime.rb:17:in `call' activesupport (3.0.3) lib/active_support/cache/strategy/local_cache.rb:72:in `call' rack (1.2.1) lib/rack/lock.rb:11:in `call' rack (1.2.1) lib/rack/lock.rb:11:in `synchronize' rack (1.2.1) lib/rack/lock.rb:11:in `call' actionpack (3.0.3) lib/action_dispatch/middleware/static.rb:30:in `call' railties (3.0.3) lib/rails/application.rb:168:in `call' railties (3.0.3) lib/rails/application.rb:77:in `send' railties (3.0.3) lib/rails/application.rb:77:in `method_missing' railties (3.0.3) lib/rails/rack/log_tailer.rb:14:in `call' rack (1.2.1) lib/rack/content_length.rb:13:in `call' rack (1.2.1) lib/rack/handler/webrick.rb:52:in `service' /system/library/frameworks/ruby.framework/versions/1.8/usr/lib/ruby/1.8/webrick/httpserver.rb:104:in `service' /system/library/frameworks/ruby.framework/versions/1.8/usr/lib/ruby/1.8/webrick/httpserver.rb:65:in `run' /system/library/frameworks/ruby.framework/versions/1.8/usr/lib/ruby/1.8/webrick/server.rb:173:in `start_thread' /system/library/frameworks/ruby.framework/versions/1.8/usr/lib/ruby/1.8/webrick/server.rb:162:in `start' /system/library/frameworks/ruby.framework/versions/1.8/usr/lib/ruby/1.8/webrick/server.rb:162:in `start_thread' /system/library/frameworks/ruby.framework/versions/1.8/usr/lib/ruby/1.8/webrick/server.rb:95:in `start' /system/library/frameworks/ruby.framework/versions/1.8/usr/lib/ruby/1.8/webrick/server.rb:92:in `each' /system/library/frameworks/ruby.framework/versions/1.8/usr/lib/ruby/1.8/webrick/server.rb:92:in `start' /system/library/frameworks/ruby.framework/versions/1.8/usr/lib/ruby/1.8/webrick/server.rb:23:in `start' /system/library/frameworks/ruby.framework/versions/1.8/usr/lib/ruby/1.8/webrick/server.rb:82:in `start' rack (1.2.1) lib/rack/handler/webrick.rb:13:in `run' rack (1.2.1) lib/rack/server.rb:213:in `start' railties (3.0.3) lib/rails/commands/server.rb:65:in `start' railties (3.0.3) lib/rails/commands.rb:30 railties (3.0.3) lib/rails/commands.rb:27:in `tap' railties (3.0.3) lib/rails/commands.rb:27 script/rails:6:in `require' script/rails:6 

the server logs show this:

started "/posts" 127.0.0.1 @ sat jul 02 22:34:51 -0700 2011   processing postscontroller#index html  ... sql statements ...  rendered layouts/_stylesheets.html.erb (1.9ms) rendered layouts/_header.html.erb (4.4ms) rendered layouts/_footer.html.erb (1.5ms) rendered posts/index.html.erb within layouts/application (18.5ms) completed   in 408ms  argumenterror (wrong number of arguments (0 1)):  rendered /library/ruby/gems/1.8/gems/actionpack-3.0.3/lib/action_dispatch/middleware/templates/rescues/_trace.erb (1.0ms) rendered /library/ruby/gems/1.8/gems/actionpack-3.0.3/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (26.5ms) rendered /library/ruby/gems/1.8/gems/actionpack-3.0.3/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb within rescues/layout (31.5ms) 

i have no idea begin debugging this. have many other complicated controllers in app , have never faced issue them, pretty sure dumb. logic in index action works without index.html.erb file (hence way template missing message). add index.html.erb file, arguments error. pretty lost this.

thanks!

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