# Error when adding 3 or 4 filters to Knowledge Explorer plugin

**URL:** <https://meta.discourse.org/t/error-when-adding-3-or-4-filters-to-knowledge-explorer-plugin/167123>\
**Category:** Bug\
**Tags:** docs\
**Created:** [October 13, 2020, 8:11pm UTC](https://meta.discourse.org/t/error-when-adding-3-or-4-filters-to-knowledge-explorer-plugin/167123 "2020-10-13T20:11:56Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![Jose\_C\_Gomez](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/jose_c_gomez/32/137297_2.png) [@Jose\_C\_Gomez](https://meta.discourse.org/u/Jose_C_Gomez)\
**Post date:** [October 13, 2020, 8:11pm UTC](https://meta.discourse.org/t/error-when-adding-3-or-4-filters-to-knowledge-explorer-plugin/167123/1 "2020-10-13T20:11:56Z")

</div>

**Bug Report:**  
If you click more than 3 or 4 filters in knowledge explorer it kind of explodes and kills your session.  
See Gif Below

 ![KnowledgeExplorer](https://global.discourse-cdn.com/meta/original/3X/3/b/3b6abc78b0e3a23d4d28112de3646ddd033efe12.gif)

> **Generates this Error**
>
> Recent  
> Message  
> ActiveRecord::StatementInvalid (PG::DuplicateAlias: ERROR: table name “t2” specified more than once  
> )  
> app/controllers/application\_controller.rb:354:in `block in with_resolved_locale' app/controllers/application_controller.rb:354:in `with\_resolved\_locale’  
> lib/middleware/omniauth\_bypass\_middleware.rb:68:in `call' lib/content_security_policy/middleware.rb:12:in `call’  
> lib/middleware/anonymous\_cache.rb:354:in `call' config/initializers/100-quiet_logger.rb:23:in `call’  
> config/initializers/100-silence\_logger.rb:31:in `call' lib/middleware/enforce_hostname.rb:22:in `call’  
> lib/middleware/request\_tracker.rb:176:in `call' Backtrace rack-mini-profiler (2.1.0) lib/patches/db/pg.rb:72:in `exec\_params’  
> rack-mini-profiler (2.1.0) lib/patches/db/pg.rb:72:in `exec_params' activerecord (6.0.3.3) lib/active_record/connection_adapters/postgresql_adapter.rb:675:in `block (2 levels) in exec\_no\_cache’  
> activesupport (6.0.3.3) lib/active\_support/dependencies/interlock.rb:48:in `block in permit_concurrent_loads' activesupport (6.0.3.3) lib/active_support/concurrency/share_lock.rb:187:in `yield\_shares’  
> activesupport (6.0.3.3) lib/active\_support/dependencies/interlock.rb:47:in `permit_concurrent_loads' activerecord (6.0.3.3) lib/active_record/connection_adapters/postgresql_adapter.rb:674:in `block in exec\_no\_cache’  
> activerecord (6.0.3.3) lib/active\_record/connection\_adapters/abstract\_adapter.rb:722:in `block (2 levels) in log' activesupport (6.0.3.3) lib/active_support/concurrency/load_interlock_aware_monitor.rb:26:in `block (2 levels) in synchronize’  
> activesupport (6.0.3.3) lib/active\_support/concurrency/load\_interlock\_aware\_monitor.rb:25:in `handle_interrupt' activesupport (6.0.3.3) lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `block in synchronize’  
> activesupport (6.0.3.3) lib/active\_support/concurrency/load\_interlock\_aware\_monitor.rb:21:in `handle_interrupt' activesupport (6.0.3.3) lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `synchronize’  
> activerecord (6.0.3.3) lib/active\_record/connection\_adapters/abstract\_adapter.rb:721:in `block in log' activesupport (6.0.3.3) lib/active_support/notifications/instrumenter.rb:24:in `instrument’  
> activerecord (6.0.3.3) lib/active\_record/connection\_adapters/abstract\_adapter.rb:712:in `log' activerecord (6.0.3.3) lib/active_record/connection_adapters/postgresql_adapter.rb:673:in `exec\_no\_cache’  
> activerecord (6.0.3.3) lib/active\_record/connection\_adapters/postgresql\_adapter.rb:654:in `execute_and_clear' activerecord (6.0.3.3) lib/active_record/connection_adapters/postgresql/database_statements.rb:98:in `exec\_query’  
> activerecord (6.0.3.3) lib/active\_record/connection\_adapters/abstract/database\_statements.rb:489:in `select' activerecord (6.0.3.3) lib/active_record/connection_adapters/abstract/database_statements.rb:70:in `select\_all’  
> activerecord (6.0.3.3) lib/active\_record/connection\_adapters/abstract/query\_cache.rb:105:in `block in select_all' activerecord (6.0.3.3) lib/active_record/connection_adapters/abstract/query_cache.rb:122:in `block in cache\_sql’  
> activesupport (6.0.3.3) lib/active\_support/concurrency/load\_interlock\_aware\_monitor.rb:26:in `block (2 levels) in synchronize' activesupport (6.0.3.3) lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `handle\_interrupt’  
> activesupport (6.0.3.3) lib/active\_support/concurrency/load\_interlock\_aware\_monitor.rb:25:in `block in synchronize' activesupport (6.0.3.3) lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `handle\_interrupt’  
> activesupport (6.0.3.3) lib/active\_support/concurrency/load\_interlock\_aware\_monitor.rb:21:in `synchronize' activerecord (6.0.3.3) lib/active_record/connection_adapters/abstract/query_cache.rb:113:in `cache\_sql’  
> activerecord (6.0.3.3) lib/active\_record/connection\_adapters/abstract/query\_cache.rb:105:in `select_all' activerecord (6.0.3.3) lib/active_record/relation/calculations.rb:346:in `block in execute\_grouped\_calculation’  
> activerecord (6.0.3.3) lib/active\_record/relation.rb:839:in `skip_query_cache_if_necessary' activerecord (6.0.3.3) lib/active_record/relation/calculations.rb:346:in `execute\_grouped\_calculation’  
> activerecord (6.0.3.3) lib/active\_record/relation/calculations.rb:250:in `perform_calculation' activerecord (6.0.3.3) lib/active_record/relation/calculations.rb:142:in `calculate’  
> activerecord (6.0.3.3) lib/active\_record/relation/calculations.rb:140:in `calculate' activerecord (6.0.3.3) lib/active_record/relation/calculations.rb:49:in `count’  
> plugins/discourse-knowledge-explorer/lib/knowledge\_explorer/query.rb:97:in `list' plugins/discourse-knowledge-explorer/app/controllers/knowledge_explorer/knowledge_explorer_controller.rb:21:in `index’  
> actionpack (6.0.3.3) lib/action\_controller/metal/basic\_implicit\_render.rb:6:in `send_action' actionpack (6.0.3.3) lib/abstract_controller/base.rb:195:in `process\_action’  
> actionpack (6.0.3.3) lib/action\_controller/metal/rendering.rb:30:in `process_action' actionpack (6.0.3.3) lib/abstract_controller/callbacks.rb:42:in `block in process\_action’  
> activesupport (6.0.3.3) lib/active\_support/callbacks.rb:112:in `block in run_callbacks' app/controllers/application_controller.rb:354:in `block in with\_resolved\_locale’  
> i18n (1.8.5) lib/i18n.rb:313:in `with_locale' app/controllers/application_controller.rb:354:in `with\_resolved\_locale’  
> activesupport (6.0.3.3) lib/active\_support/callbacks.rb:121:in `block in run_callbacks' activesupport (6.0.3.3) lib/active_support/callbacks.rb:139:in `run\_callbacks’  
> actionpack (6.0.3.3) lib/abstract\_controller/callbacks.rb:41:in `process_action' actionpack (6.0.3.3) lib/action_controller/metal/rescue.rb:22:in `process\_action’  
> actionpack (6.0.3.3) lib/action\_controller/metal/instrumentation.rb:33:in `block in process_action' activesupport (6.0.3.3) lib/active_support/notifications.rb:180:in `block in instrument’  
> activesupport (6.0.3.3) lib/active\_support/notifications/instrumenter.rb:24:in `instrument' activesupport (6.0.3.3) lib/active_support/notifications.rb:180:in `instrument’  
> actionpack (6.0.3.3) lib/action\_controller/metal/instrumentation.rb:32:in `process_action' actionpack (6.0.3.3) lib/action_controller/metal/params_wrapper.rb:245:in `process\_action’  
> activerecord (6.0.3.3) lib/active\_record/railties/controller\_runtime.rb:27:in `process_action' actionpack (6.0.3.3) lib/abstract_controller/base.rb:136:in `process’  
> actionview (6.0.3.3) lib/action\_view/rendering.rb:39:in `process' rack-mini-profiler (2.1.0) lib/mini_profiler/profiling_methods.rb:104:in `block in profile\_method’  
> actionpack (6.0.3.3) lib/action\_controller/metal.rb:190:in `dispatch' actionpack (6.0.3.3) lib/action_controller/metal.rb:254:in `dispatch’  
> actionpack (6.0.3.3) lib/action\_dispatch/routing/route\_set.rb:50:in `dispatch' actionpack (6.0.3.3) lib/action_dispatch/routing/route_set.rb:33:in `serve’  
> actionpack (6.0.3.3) lib/action\_dispatch/routing/mapper.rb:18:in `block in <class:Constraints>' actionpack (6.0.3.3) lib/action_dispatch/routing/mapper.rb:48:in `serve’  
> actionpack (6.0.3.3) lib/action\_dispatch/journey/router.rb:49:in `block in serve' actionpack (6.0.3.3) lib/action_dispatch/journey/router.rb:32:in `each’  
> actionpack (6.0.3.3) lib/action\_dispatch/journey/router.rb:32:in `serve' actionpack (6.0.3.3) lib/action_dispatch/routing/route_set.rb:834:in `call’  
> railties (6.0.3.3) lib/rails/engine.rb:527:in `call' railties (6.0.3.3) lib/rails/railtie.rb:190:in `public\_send’  
> railties (6.0.3.3) lib/rails/railtie.rb:190:in `method_missing' actionpack (6.0.3.3) lib/action_dispatch/routing/mapper.rb:19:in `block in class:Constraints’  
> actionpack (6.0.3.3) lib/action\_dispatch/routing/mapper.rb:48:in `serve' actionpack (6.0.3.3) lib/action_dispatch/journey/router.rb:49:in `block in serve’  
> actionpack (6.0.3.3) lib/action\_dispatch/journey/router.rb:32:in `each' actionpack (6.0.3.3) lib/action_dispatch/journey/router.rb:32:in `serve’  
> actionpack (6.0.3.3) lib/action\_dispatch/routing/route\_set.rb:834:in `call' lib/middleware/omniauth_bypass_middleware.rb:68:in `call’  
> rack (2.2.3) lib/rack/tempfile\_reaper.rb:15:in `call' rack (2.2.3) lib/rack/conditional_get.rb:27:in `call’  
> rack (2.2.3) lib/rack/head.rb:12:in `call' lib/content_security_policy/middleware.rb:12:in `call’  
> lib/middleware/anonymous\_cache.rb:354:in `call' rack (2.2.3) lib/rack/session/abstract/id.rb:266:in `context’  
> rack (2.2.3) lib/rack/session/abstract/id.rb:260:in `call' actionpack (6.0.3.3) lib/action_dispatch/middleware/cookies.rb:648:in `call’  
> actionpack (6.0.3.3) lib/action\_dispatch/middleware/callbacks.rb:27:in `block in call' activesupport (6.0.3.3) lib/active_support/callbacks.rb:101:in `run\_callbacks’  
> actionpack (6.0.3.3) lib/action\_dispatch/middleware/callbacks.rb:26:in `call' actionpack (6.0.3.3) lib/action_dispatch/middleware/actionable_exceptions.rb:17:in `call’  
> actionpack (6.0.3.3) lib/action\_dispatch/middleware/debug\_exceptions.rb:32:in `call' actionpack (6.0.3.3) lib/action_dispatch/middleware/show_exceptions.rb:33:in `call’  
> logster (2.9.4) lib/logster/middleware/reporter.rb:43:in `call' railties (6.0.3.3) lib/rails/rack/logger.rb:37:in `call\_app’  
> railties (6.0.3.3) lib/rails/rack/logger.rb:28:in `call' config/initializers/100-quiet_logger.rb:23:in `call’  
> config/initializers/100-silence\_logger.rb:31:in `call' actionpack (6.0.3.3) lib/action_dispatch/middleware/remote_ip.rb:81:in `call’  
> actionpack (6.0.3.3) lib/action\_dispatch/middleware/request\_id.rb:27:in `call' lib/middleware/enforce_hostname.rb:22:in `call’  
> rack (2.2.3) lib/rack/method\_override.rb:24:in `call' actionpack (6.0.3.3) lib/action_dispatch/middleware/executor.rb:14:in `call’  
> rack (2.2.3) lib/rack/sendfile.rb:110:in `call’  
> actionpack (6.0.3.3) lib/action\_dispatch/middleware/host\_authorization.rb  
> Env  
> hostname doclx-app  
> process\_id 5275  
> application\_version e54c8a998bae0dd2ec025a8da3281e23523f9228  
> HTTP\_HOST   
> REQUEST\_URI /docs.json?category=5&tags=apinvhed|ap-invoice-entry|bpm-data-form  
> REQUEST\_METHOD GET  
> HTTP\_USER\_AGENT Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.121 Safari/537.36  
> HTTP\_ACCEPT application/json, text/javascript, _/_; q=0.01  
> HTTP\_REFERER https:///docs?category=5&tags=apinvhed%7Cap-invoice-entry  
> HTTP\_X\_FORWARDED\_FOR 10.81.20.163  
> HTTP\_X\_REAL\_IP 10.81.20.163  
> username jcgomez  
> params   
> category 5  
> tags apinvhed|ap-invoice-entry|bpm-data-form  
> Solve Remove Protect Copy

---

<div class="post-metadata">

**Author:** ![justin](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/justin/32/157614_2.png) [@justin](https://meta.discourse.org/u/justin)\
**Post date:** [October 13, 2020, 9:13pm UTC](https://meta.discourse.org/t/error-when-adding-3-or-4-filters-to-knowledge-explorer-plugin/167123/4 "2020-10-13T21:13:37Z")

</div>

Thanks for the report! We can reproduce this. I’ll have a look into it.

---

<div class="post-metadata">

**Author:** ![justin](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/justin/32/157614_2.png) [@justin](https://meta.discourse.org/u/justin)\
**Post date:** [October 13, 2020, 10:18pm UTC](https://meta.discourse.org/t/error-when-adding-3-or-4-filters-to-knowledge-explorer-plugin/167123/5 "2020-10-13T22:18:07Z")

</div>

PR is up for a fix here! Will merge as soon as I get a second set of eyes on it.

[https://github.com/discourse/discourse-knowledge-explorer/pull/12](https://github.com/discourse/discourse-knowledge-explorer/pull/12)

---

<div class="post-metadata">

**Author:** ![Jose\_C\_Gomez](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/jose_c_gomez/32/137297_2.png) [@Jose\_C\_Gomez](https://meta.discourse.org/u/Jose_C_Gomez)\
**Post date:** [October 13, 2020, 11:12pm UTC](https://meta.discourse.org/t/error-when-adding-3-or-4-filters-to-knowledge-explorer-plugin/167123/6 "2020-10-13T23:12:44Z")

</div>

Awesome thank you @justin!!!

---

<div class="post-metadata">

**Author:** ![justin](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/justin/32/157614_2.png) [@justin](https://meta.discourse.org/u/justin)\
**Post date:** [October 14, 2020, 2:27pm UTC](https://meta.discourse.org/t/error-when-adding-3-or-4-filters-to-knowledge-explorer-plugin/167123/7 "2020-10-14T14:27:41Z")

</div>

Fixed here!

[https://github.com/discourse/discourse-knowledge-explorer/commit/795935515994be42b1a0d0257dd0fcb8fb1e3913](https://github.com/discourse/discourse-knowledge-explorer/commit/795935515994be42b1a0d0257dd0fcb8fb1e3913)

---

<div class="post-metadata">

**Author:** ![justin](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/justin/32/157614_2.png) [@justin](https://meta.discourse.org/u/justin)\
**Post date:** [October 14, 2020, 2:27pm UTC](https://meta.discourse.org/t/error-when-adding-3-or-4-filters-to-knowledge-explorer-plugin/167123/8 "2020-10-14T14:27:45Z")

</div>