# Polls plugin causing 500 error on post save

**URL:** https://meta.discourse.org/t/polls-plugin-causing-500-error-on-post-save/146248
**Category:** Development
**Created:** [March 31, 2020, 8:54am UTC](https://meta.discourse.org/t/polls-plugin-causing-500-error-on-post-save/146248 "2020-03-31T08:54:21Z")
**Posts on this page:** 4
**Page:** 1

<div class="post-metadata">

### Author: ![benbowler](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/benbowler/32/174749_2.png) [@benbowler](https://meta.discourse.org/u/benbowler)
#### Post date: [March 31, 2020, 8:54am UTC](https://meta.discourse.org/t/polls-plugin-causing-500-error-on-post-save/146248/1 "2020-03-31T08:54:21Z")

</div>

On the latest version of Discourse on Docker I’m having the reverse of this issue: [Polls disabled caused 500 error](https://meta.discourse.org/t/polls-disabled-caused-500-error/93216)

If polls are **enabled** replying to a topic shows a 500 error. Trace:

```plaintext
NoMethodError in PostsController#create

undefined method `polls' for #<Post:0x00007fa2b3502050>
Extracted source (around line #431):

#429 else
#430 match = matched_attribute_method(method.to_s)
*431 match ? attribute_missing(match, *args, &block) : super
#432 end
#433 end
#434 

Extracted source (around line #552):

#550 
#551 unless post.is_first_post?
*552 polls = ActiveModel::ArraySerializer.new(post.polls, each_serializer: PollSerializer, root: false, scope: guardian).as_json
#553 post.publish_message!("/polls/#{post.topic_id}", post_id: post.id, polls: polls)
#554 end
#555 end

Extracted source (around line #326):

#324 def on(event_name, &block)
#325 DiscourseEvent.on(event_name) do |*args|
*326 block.call(*args) if enabled?
#327 end
#328 end
#329 

Rails.root: /src

Application Trace
lib/plugin/instance.rb:326:in `block in on'
lib/discourse_event.rb:14:in `block in trigger'
lib/discourse_event.rb:13:in `trigger'
lib/post_creator.rb:239:in `trigger_after_events'
lib/post_creator.rb:208:in `create'
lib/new_post_manager.rb:271:in `perform_create_post'
lib/new_post_manager.rb:209:in `perform'
app/controllers/posts_controller.rb:179:in `create'
lib/middleware/omniauth_bypass_middleware.rb:68:in `call'
lib/content_security_policy/middleware.rb:12:in `call'
config/initializers/100-quiet_logger.rb:18:in `call'
config/initializers/100-silence_logger.rb:31:in `call'
lib/middleware/missing_avatars.rb:23:in `call'
lib/middleware/turbo_dev.rb:34:in `call'

Framework Trace
activemodel (6.0.1) lib/active_model/attribute_methods.rb:431:in `method_missing'
plugins/poll/plugin.rb:552:in `block (2 levels) in activate!'
/usr/local/lib/ruby/2.6.0/set.rb:338:in `each_key'
/usr/local/lib/ruby/2.6.0/set.rb:338:in `each'
actionpack (6.0.1) lib/action_controller/metal/basic_implicit_render.rb:6:in `send_action'
actionpack (6.0.1) lib/abstract_controller/base.rb:196:in `process_action'
actionpack (6.0.1) lib/action_controller/metal/rendering.rb:30:in `process_action'
actionpack (6.0.1) lib/abstract_controller/callbacks.rb:42:in `block in process_action'
activesupport (6.0.1) lib/active_support/callbacks.rb:135:in `run_callbacks'
actionpack (6.0.1) lib/abstract_controller/callbacks.rb:41:in `process_action'
actionpack (6.0.1) lib/action_controller/metal/rescue.rb:22:in `process_action'
actionpack (6.0.1) lib/action_controller/metal/instrumentation.rb:33:in `block in process_action'
activesupport (6.0.1) lib/active_support/notifications.rb:180:in `block in instrument'
activesupport (6.0.1) lib/active_support/notifications/instrumenter.rb:24:in `instrument'
activesupport (6.0.1) lib/active_support/notifications.rb:180:in `instrument'
actionpack (6.0.1) lib/action_controller/metal/instrumentation.rb:32:in `process_action'
actionpack (6.0.1) lib/action_controller/metal/params_wrapper.rb:245:in `process_action'
activerecord (6.0.1) lib/active_record/railties/controller_runtime.rb:27:in `process_action'
actionpack (6.0.1) lib/abstract_controller/base.rb:136:in `process'
actionview (6.0.1) lib/action_view/rendering.rb:39:in `process'
rack-mini-profiler (2.0.1) lib/mini_profiler/profiling_methods.rb:104:in `block in profile_method'
actionpack (6.0.1) lib/action_controller/metal.rb:191:in `dispatch'
actionpack (6.0.1) lib/action_controller/metal.rb:252:in `dispatch'
actionpack (6.0.1) lib/action_dispatch/routing/route_set.rb:51:in `dispatch'
actionpack (6.0.1) lib/action_dispatch/routing/route_set.rb:33:in `serve'
actionpack (6.0.1) lib/action_dispatch/journey/router.rb:49:in `block in serve'
actionpack (6.0.1) lib/action_dispatch/journey/router.rb:32:in `each'
actionpack (6.0.1) lib/action_dispatch/journey/router.rb:32:in `serve'
actionpack (6.0.1) lib/action_dispatch/routing/route_set.rb:837:in `call'
rack (2.0.8) lib/rack/tempfile_reaper.rb:15:in `call'
rack (2.0.8) lib/rack/conditional_get.rb:38:in `call'
rack (2.0.8) lib/rack/head.rb:12:in `call'
rack (2.0.8) lib/rack/session/abstract/id.rb:259:in `context'
rack (2.0.8) lib/rack/session/abstract/id.rb:253:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/cookies.rb:648:in `call'
activerecord (6.0.1) lib/active_record/migration.rb:567:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/callbacks.rb:27:in `block in call'
activesupport (6.0.1) lib/active_support/callbacks.rb:101:in `run_callbacks'
actionpack (6.0.1) lib/action_dispatch/middleware/callbacks.rb:26:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/executor.rb:14:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/actionable_exceptions.rb:17:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/debug_exceptions.rb:32:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/show_exceptions.rb:33:in `call'
logster (2.7.1) lib/logster/middleware/reporter.rb:43:in `call'
railties (6.0.1) lib/rails/rack/logger.rb:38:in `call_app'
railties (6.0.1) lib/rails/rack/logger.rb:28:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/remote_ip.rb:81:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/request_id.rb:27:in `call'
rack (2.0.8) lib/rack/method_override.rb:22:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/executor.rb:14:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/static.rb:126:in `call'
rack (2.0.8) lib/rack/sendfile.rb:111:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/host_authorization.rb:83:in `call'
rack-mini-profiler (2.0.1) lib/mini_profiler/profiler.rb:312:in `call'
message_bus (2.2.4) lib/message_bus/rack/middleware.rb:57:in `call'
railties (6.0.1) lib/rails/engine.rb:526:in `call'
railties (6.0.1) lib/rails/railtie.rb:190:in `public_send'
railties (6.0.1) lib/rails/railtie.rb:190:in `method_missing'
rack (2.0.8) lib/rack/urlmap.rb:68:in `block in call'
rack (2.0.8) lib/rack/urlmap.rb:53:in `each'
rack (2.0.8) lib/rack/urlmap.rb:53:in `call'
unicorn (5.5.4) lib/unicorn/http_server.rb:605:in `process_client'
unicorn (5.5.4) lib/unicorn/http_server.rb:700:in `worker_loop'
unicorn (5.5.4) lib/unicorn/http_server.rb:548:in `spawn_missing_workers'
unicorn (5.5.4) lib/unicorn/http_server.rb:144:in `start'
unicorn (5.5.4) bin/unicorn:128:in `<top (required)>'
bin/unicorn:87:in `load'
bin/unicorn:87:in `block in <main>'
bin/unicorn:86:in `fork'
bin/unicorn:86:in `<main>'

Full Trace
activemodel (6.0.1) lib/active_model/attribute_methods.rb:431:in `method_missing'
plugins/poll/plugin.rb:552:in `block (2 levels) in activate!'
lib/plugin/instance.rb:326:in `block in on'
lib/discourse_event.rb:14:in `block in trigger'
/usr/local/lib/ruby/2.6.0/set.rb:338:in `each_key'
/usr/local/lib/ruby/2.6.0/set.rb:338:in `each'
lib/discourse_event.rb:13:in `trigger'
lib/post_creator.rb:239:in `trigger_after_events'
lib/post_creator.rb:208:in `create'
lib/new_post_manager.rb:271:in `perform_create_post'
lib/new_post_manager.rb:209:in `perform'
app/controllers/posts_controller.rb:179:in `create'
actionpack (6.0.1) lib/action_controller/metal/basic_implicit_render.rb:6:in `send_action'
actionpack (6.0.1) lib/abstract_controller/base.rb:196:in `process_action'
actionpack (6.0.1) lib/action_controller/metal/rendering.rb:30:in `process_action'
actionpack (6.0.1) lib/abstract_controller/callbacks.rb:42:in `block in process_action'
activesupport (6.0.1) lib/active_support/callbacks.rb:135:in `run_callbacks'
actionpack (6.0.1) lib/abstract_controller/callbacks.rb:41:in `process_action'
actionpack (6.0.1) lib/action_controller/metal/rescue.rb:22:in `process_action'
actionpack (6.0.1) lib/action_controller/metal/instrumentation.rb:33:in `block in process_action'
activesupport (6.0.1) lib/active_support/notifications.rb:180:in `block in instrument'
activesupport (6.0.1) lib/active_support/notifications/instrumenter.rb:24:in `instrument'
activesupport (6.0.1) lib/active_support/notifications.rb:180:in `instrument'
actionpack (6.0.1) lib/action_controller/metal/instrumentation.rb:32:in `process_action'
actionpack (6.0.1) lib/action_controller/metal/params_wrapper.rb:245:in `process_action'
activerecord (6.0.1) lib/active_record/railties/controller_runtime.rb:27:in `process_action'
actionpack (6.0.1) lib/abstract_controller/base.rb:136:in `process'
actionview (6.0.1) lib/action_view/rendering.rb:39:in `process'
rack-mini-profiler (2.0.1) lib/mini_profiler/profiling_methods.rb:104:in `block in profile_method'
actionpack (6.0.1) lib/action_controller/metal.rb:191:in `dispatch'
actionpack (6.0.1) lib/action_controller/metal.rb:252:in `dispatch'
actionpack (6.0.1) lib/action_dispatch/routing/route_set.rb:51:in `dispatch'
actionpack (6.0.1) lib/action_dispatch/routing/route_set.rb:33:in `serve'
actionpack (6.0.1) lib/action_dispatch/journey/router.rb:49:in `block in serve'
actionpack (6.0.1) lib/action_dispatch/journey/router.rb:32:in `each'
actionpack (6.0.1) lib/action_dispatch/journey/router.rb:32:in `serve'
actionpack (6.0.1) lib/action_dispatch/routing/route_set.rb:837:in `call'
lib/middleware/omniauth_bypass_middleware.rb:68:in `call'
rack (2.0.8) lib/rack/tempfile_reaper.rb:15:in `call'
rack (2.0.8) lib/rack/conditional_get.rb:38:in `call'
rack (2.0.8) lib/rack/head.rb:12:in `call'
lib/content_security_policy/middleware.rb:12:in `call'
rack (2.0.8) lib/rack/session/abstract/id.rb:259:in `context'
rack (2.0.8) lib/rack/session/abstract/id.rb:253:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/cookies.rb:648:in `call'
activerecord (6.0.1) lib/active_record/migration.rb:567:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/callbacks.rb:27:in `block in call'
activesupport (6.0.1) lib/active_support/callbacks.rb:101:in `run_callbacks'
actionpack (6.0.1) lib/action_dispatch/middleware/callbacks.rb:26:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/executor.rb:14:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/actionable_exceptions.rb:17:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/debug_exceptions.rb:32:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/show_exceptions.rb:33:in `call'
logster (2.7.1) lib/logster/middleware/reporter.rb:43:in `call'
railties (6.0.1) lib/rails/rack/logger.rb:38:in `call_app'
railties (6.0.1) lib/rails/rack/logger.rb:28:in `call'
config/initializers/100-quiet_logger.rb:18:in `call'
config/initializers/100-silence_logger.rb:31:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/remote_ip.rb:81:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/request_id.rb:27:in `call'
rack (2.0.8) lib/rack/method_override.rb:22:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/executor.rb:14:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/static.rb:126:in `call'
rack (2.0.8) lib/rack/sendfile.rb:111:in `call'
actionpack (6.0.1) lib/action_dispatch/middleware/host_authorization.rb:83:in `call'
lib/middleware/missing_avatars.rb:23:in `call'
lib/middleware/turbo_dev.rb:34:in `call'
rack-mini-profiler (2.0.1) lib/mini_profiler/profiler.rb:312:in `call'
message_bus (2.2.4) lib/message_bus/rack/middleware.rb:57:in `call'
railties (6.0.1) lib/rails/engine.rb:526:in `call'
railties (6.0.1) lib/rails/railtie.rb:190:in `public_send'
railties (6.0.1) lib/rails/railtie.rb:190:in `method_missing'
rack (2.0.8) lib/rack/urlmap.rb:68:in `block in call'
rack (2.0.8) lib/rack/urlmap.rb:53:in `each'
rack (2.0.8) lib/rack/urlmap.rb:53:in `call'
unicorn (5.5.4) lib/unicorn/http_server.rb:605:in `process_client'
unicorn (5.5.4) lib/unicorn/http_server.rb:700:in `worker_loop'
unicorn (5.5.4) lib/unicorn/http_server.rb:548:in `spawn_missing_workers'
unicorn (5.5.4) lib/unicorn/http_server.rb:144:in `start'
unicorn (5.5.4) bin/unicorn:128:in `<top (required)>'
bin/unicorn:87:in `load'
bin/unicorn:87:in `block in <main>'
bin/unicorn:86:in `fork'
bin/unicorn:86:in `<main>'

```

---

<div class="post-metadata">

### Author: ![david](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/david/32/157490_2.png) [@david](https://meta.discourse.org/u/david)
#### Post date: [March 31, 2020, 10:35am UTC](https://meta.discourse.org/t/polls-plugin-causing-500-error-on-post-save/146248/4 "2020-03-31T10:35:45Z")

</div>

Hi Ben, it seems like you are missing some database migrations from the polls plugin. Can you tell us more about how you have Discourse set up? Did you follow our standard installation guide?

---

<div class="post-metadata">

### Author: ![sam](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/sam/32/102149_2.png) [@sam](https://meta.discourse.org/u/sam)
#### Post date: [April 1, 2020, 1:11am UTC](https://meta.discourse.org/t/polls-plugin-causing-500-error-on-post-save/146248/6 "2020-04-01T01:11:40Z")

</div>

A simple workaround here is:

```plaintext
cd /var/discourse
./launcher rebuild app

```

My guess is that somehow migrations did not fire correctly when you did an upgrade or restore.

---

<div class="post-metadata">

### Author: ![benbowler](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/benbowler/32/174749_2.png) [@benbowler](https://meta.discourse.org/u/benbowler)
#### Post date: [April 1, 2020, 5:08pm UTC](https://meta.discourse.org/t/polls-plugin-causing-500-error-on-post-save/146248/7 "2020-04-01T17:08:25Z")

</div>

Hey guys, I’m developing a plugin so I went the discourse\_docker route. I’ve actually submitted a pr for the instructions there. There are a few other steps missing if you’d like to to elaborate. Up and running now with the polls plugin disabled - it doesn’t impact my testing.