A user is troubleshooting an Internal Server Error 500 while configuring Discourse AI and Manual LLMs on a self-hosted forum. viswanatha reports the error and shares logs showing a NoMethodError related to max_prompt_tokens and a 400 error from the OpenAI endpoint indicating the messages array is too short. Roman suggests checking required fields, and viswanatha confirms the issue stems from missing context window settings. Further investigation reveals the error occurs when the “Enable response API” option is enabled. viswanatha notes that disabling this option resolves the test failure. A successful cURL request to Ollama using the deepseek-coder-v2:latest model confirms the API is working, indicating the issue is likely with the Discourse AI plugin configuration rather than the model itself. viswanatha shares the cURL response as evidence.
I have a self-hosted Discourse forum, and I am encountering an Internal Server Error while configuring Discourse AI and the Manual LLMs. How can I resolve this issue? Could you please share any helpful guides to assist me further?
Error screenshots
Failed to load resource: the server responded with a status of 500 ()
screenshots Steps performed:
Check your /logs route and see if there is more information about the error there. IIRC, Ollama needs something in the API key field, even if not used.
Below are the logs
info Message
NoMethodError (undefined method `-' for nil)
app/controllers/application_controller.rb:428:in `block in with_resolved_locale'
app/controllers/application_controller.rb:428:in `with_resolved_locale'
lib/middleware/omniauth_bypass_middleware.rb:35:in `call'
lib/content_security_policy/middleware.rb:12:in `call'
lib/middleware/anonymous_cache.rb:415:in `call'
lib/middleware/csp_script_nonce_injector.rb:12:in `call'
config/initializers/008-rack-cors.rb:14:in `call'
lib/middleware/default_headers.rb:13:in `call'
config/initializers/100-quiet_logger.rb:20:in `call'
config/initializers/100-silence_logger.rb:29:in `call'
lib/middleware/enforce_hostname.rb:23:in `call'
lib/middleware/processing_request.rb:12:in `call'
lib/middleware/request_tracker.rb:410:in `call'
Backtrace
plugins/discourse-ai/lib/completions/dialects/chat_gpt.rb:47:in `max_prompt_tokens'
plugins/discourse-ai/lib/completions/dialects/dialect.rb:134:in `trim_messages'
plugins/discourse-ai/lib/completions/dialects/dialect.rb:83:in `translate'
plugins/discourse-ai/lib/completions/endpoints/base.rb:123:in `perform_completion!'
plugins/discourse-ai/lib/completions/endpoints/open_ai.rb:53:in `perform_completion!'
plugins/discourse-ai/lib/completions/llm.rb:415:in `generate'
plugins/discourse-ai/lib/configuration/llm_validator.rb:36:in `run_test'
plugins/discourse-ai/app/controllers/discourse_ai/admin/ai_llms_controller.rb:143:in `test'
actionpack (8.0.2.1) lib/action_controller/metal/basic_implicit_render.rb:8:in `send_action'
actionpack (8.0.2.1) lib/abstract_controller/base.rb:226:in `process_action'
actionpack (8.0.2.1) lib/action_controller/metal/rendering.rb:193:in `process_action'
actionpack (8.0.2.1) lib/abstract_controller/callbacks.rb:261:in `block in process_action'
activesupport (8.0.2.1) lib/active_support/callbacks.rb:120:in `block in run_callbacks'
app/controllers/application_controller.rb:428:in `block in with_resolved_locale'
i18n (1.14.7) lib/i18n.rb:353:in `with_locale'
app/controllers/application_controller.rb:428:in `with_resolved_locale'
activesupport (8.0.2.1) lib/active_support/callbacks.rb:129:in `block in run_callbacks'
activesupport (8.0.2.1) lib/active_support/callbacks.rb:140:in `run_callbacks'
actionpack (8.0.2.1) lib/abstract_controller/callbacks.rb:260:in `process_action'
actionpack (8.0.2.1) lib/action_controller/metal/rescue.rb:27:in `process_action'
actionpack (8.0.2.1) lib/action_controller/metal/instrumentation.rb:76:in `block in process_action'
activesupport (8.0.2.1) lib/active_support/notifications.rb:210:in `block in instrument'
activesupport (8.0.2.1) lib/active_support/notifications/instrumenter.rb:58:in `instrument'
activesupport (8.0.2.1) lib/active_support/notifications.rb:210:in `instrument'
actionpack (8.0.2.1) lib/action_controller/metal/instrumentation.rb:75:in `process_action'
actionpack (8.0.2.1) lib/action_controller/metal/params_wrapper.rb:259:in `process_action'
activerecord (8.0.2.1) lib/active_record/railties/controller_runtime.rb:39:in `process_action'
actionpack (8.0.2.1) lib/abstract_controller/base.rb:163:in `process'
actionview (8.0.2.1) lib/action_view/rendering.rb:40:in `process'
rack-mini-profiler (4.0.1) lib/mini_profiler/profiling_methods.rb:116:in `block in profile_method'
actionpack (8.0.2.1) lib/action_controller/metal.rb:252:in `dispatch'
actionpack (8.0.2.1) lib/action_controller/metal.rb:335:in `dispatch'
actionpack (8.0.2.1) lib/action_dispatch/routing/route_set.rb:67:in `dispatch'
actionpack (8.0.2.1) lib/action_dispatch/routing/route_set.rb:50:in `serve'
actionpack (8.0.2.1) lib/action_dispatch/routing/mapper.rb:32:in `block in <class:Constraints>'
actionpack (8.0.2.1) lib/action_dispatch/routing/mapper.rb:62:in `serve'
actionpack (8.0.2.1) lib/action_dispatch/journey/router.rb:53:in `block in serve'
actionpack (8.0.2.1) lib/action_dispatch/journey/router.rb:133:in `block in find_routes'
actionpack (8.0.2.1) lib/action_dispatch/journey/router.rb:126:in `each'
actionpack (8.0.2.1) lib/action_dispatch/journey/router.rb:126:in `find_routes'
actionpack (8.0.2.1) lib/action_dispatch/journey/router.rb:34:in `serve'
actionpack (8.0.2.1) lib/action_dispatch/routing/route_set.rb:908:in `call'
lib/middleware/omniauth_bypass_middleware.rb:35:in `call'
rack (2.2.17) lib/rack/tempfile_reaper.rb:15:in `call'
rack (2.2.17) lib/rack/conditional_get.rb:27:in `call'
rack (2.2.17) lib/rack/head.rb:12:in `call'
actionpack (8.0.2.1) lib/action_dispatch/http/permissions_policy.rb:38:in `call'
lib/content_security_policy/middleware.rb:12:in `call'
lib/middleware/anonymous_cache.rb:415:in `call'
lib/middleware/csp_script_nonce_injector.rb:12:in `call'
config/initializers/008-rack-cors.rb:14:in `call'
rack (2.2.17) lib/rack/session/abstract/id.rb:266:in `context'
rack (2.2.17) lib/rack/session/abstract/id.rb:260:in `call'
actionpack (8.0.2.1) lib/action_dispatch/middleware/cookies.rb:706:in `call'
actionpack (8.0.2.1) lib/action_dispatch/middleware/callbacks.rb:31:in `block in call'
activesupport (8.0.2.1) lib/active_support/callbacks.rb:100:in `run_callbacks'
actionpack (8.0.2.1) lib/action_dispatch/middleware/callbacks.rb:30:in `call'
actionpack (8.0.2.1) lib/action_dispatch/middleware/debug_exceptions.rb:31:in `call'
actionpack (8.0.2.1) lib/action_dispatch/middleware/show_exceptions.rb:32:in `call'
logster (2.20.1) lib/logster/middleware/reporter.rb:40:in `call'
lib/middleware/default_headers.rb:13:in `call'
railties (8.0.2.1) lib/rails/rack/logger.rb:41:in `call_app'
railties (8.0.2.1) lib/rails/rack/logger.rb:29:in `call'
config/initializers/100-quiet_logger.rb:20:in `call'
config/initializers/100-silence_logger.rb:29:in `call'
actionpack (8.0.2.1) lib/action_dispatch/middleware/request_id.rb:34:in `call'
lib/middleware/enforce_hostname.rb:23:in `call'
rack (2.2.17) lib/rack/method_override.rb:24:in `call'
actionpack (8.0.2.1) lib/action_dispatch/middleware/executor.rb:16:in `call'
rack (2.2.17) lib/rack/sendfile.rb:110:in `call'
rack-mini-profiler (4.0.1) lib/mini_profiler.rb:334:in `call'
lib/middleware/processing_request.rb:12:in `call'
message_bus (4.4.1) lib/message_bus/rack/middleware.rb:60:in `call'
lib/middleware/request_tracker.rb:410:in `call'
actionpack (8.0.2.1) lib/action_dispatch/middleware/remote_ip.rb:96:in `call'
railties (8.0.2.1) lib/rails/engine.rb:535:in `call'
railties (8.0.2.1) lib/rails/railtie.rb:226:in `public_send'
railties (8.0.2.1) lib/rails/railtie.rb:226:in `method_missing'
rack (2.2.17) lib/rack/urlmap.rb:74:in `block in call'
rack (2.2.17) lib/rack/urlmap.rb:58:in `each'
rack (2.2.17) lib/rack/urlmap.rb:58:in `call'
unicorn (6.1.0) lib/unicorn/http_server.rb:634:in `process_client'
unicorn (6.1.0) lib/unicorn/http_server.rb:739:in `worker_loop'
unicorn (6.1.0) lib/unicorn/http_server.rb:547:in `spawn_missing_workers'
unicorn (6.1.0) lib/unicorn/http_server.rb:143:in `start'
unicorn (6.1.0) bin/unicorn:128:in `<top (required)>'
vendor/bundle/ruby/3.3.0/bin/unicorn:25:in `load'
vendor/bundle/ruby/3.3.0/bin/unicorn:25:in `<main>'
You need to fill all the required fields to run the test. The error you shared happens because you didn’t specify a context window for the model.
Error Message :
Trying to contact the model returned this error: {"error":{"message":"[] is too short - 'messages'","type":"invalid_request_error","param":null,"code":null}}
Message (2 copies reported)
DiscourseAi::Completions::Endpoints::OpenAi: status: 400 - body: {"error":{"message":"[] is too short - 'messages'","type":"invalid_request_error","param":null,"code":null}}
Backtrace
activesupport-8.0.2.1/lib/active_support/broadcast_logger.rb:134:in `block in error'
activesupport-8.0.2.1/lib/active_support/broadcast_logger.rb:231:in `block in dispatch'
activesupport-8.0.2.1/lib/active_support/broadcast_logger.rb:231:in `each'
activesupport-8.0.2.1/lib/active_support/broadcast_logger.rb:231:in `dispatch'
activesupport-8.0.2.1/lib/active_support/broadcast_logger.rb:134:in `error'
/var/www/discourse/plugins/discourse-ai/lib/completions/endpoints/base.rb:170:in `block (2 levels) in perform_completion!'
net-http-0.6.0/lib/net/http.rb:2433:in `block in transport_request'
net-http-0.6.0/lib/net/http/response.rb:320:in `reading_body'
net-http-0.6.0/lib/net/http.rb:2430:in `transport_request'
net-http-0.6.0/lib/net/http.rb:2384:in `request'
rack-mini-profiler-4.0.1/lib/patches/net_patches.rb:19:in `block in request_with_mini_profiler'
rack-mini-profiler-4.0.1/lib/mini_profiler/profiling_methods.rb:45:in `step'
rack-mini-profiler-4.0.1/lib/patches/net_patches.rb:18:in `request_with_mini_profiler'
/var/www/discourse/plugins/discourse-ai/lib/completions/endpoints/base.rb:168:in `block in perform_completion!'
net-http-0.6.0/lib/net/http.rb:1632:in `start'
net-http-0.6.0/lib/net/http.rb:1070:in `start'
/var/www/discourse/plugins/discourse-ai/lib/completions/endpoints/base.rb:139:in `perform_completion!'
/var/www/discourse/plugins/discourse-ai/lib/completions/endpoints/open_ai.rb:53:in `perform_completion!'
/var/www/discourse/plugins/discourse-ai/lib/completions/llm.rb:415:in `generate'
/var/www/discourse/plugins/discourse-ai/lib/configuration/llm_validator.rb:36:in `run_test'
/var/www/discourse/plugins/discourse-ai/app/controllers/discourse_ai/admin/ai_llms_controller.rb:143:in `test'
actionpack-8.0.2.1/lib/action_controller/metal/basic_implicit_render.rb:8:in `send_action'
actionpack-8.0.2.1/lib/abstract_controller/base.rb:226:in `process_action'
actionpack-8.0.2.1/lib/action_controller/metal/rendering.rb:193:in `process_action'
actionpack-8.0.2.1/lib/abstract_controller/callbacks.rb:261:in `block in process_action'
activesupport-8.0.2.1/lib/active_support/callbacks.rb:120:in `block in run_callbacks'
/var/www/discourse/app/controllers/application_controller.rb:428:in `block in with_resolved_locale'
i18n-1.14.7/lib/i18n.rb:353:in `with_locale'
/var/www/discourse/app/controllers/application_controller.rb:428:in `with_resolved_locale'
activesupport-8.0.2.1/lib/active_support/callbacks.rb:129:in `block in run_callbacks'
activesupport-8.0.2.1/lib/active_support/callbacks.rb:140:in `run_callbacks'
actionpack-8.0.2.1/lib/abstract_controller/callbacks.rb:260:in `process_action'
actionpack-8.0.2.1/lib/action_controller/metal/rescue.rb:27:in `process_action'
actionpack-8.0.2.1/lib/action_controller/metal/instrumentation.rb:76:in `block in process_action'
activesupport-8.0.2.1/lib/active_support/notifications.rb:210:in `block in instrument'
activesupport-8.0.2.1/lib/active_support/notifications/instrumenter.rb:58:in `instrument'
activesupport-8.0.2.1/lib/active_support/notifications.rb:210:in `instrument'
actionpack-8.0.2.1/lib/action_controller/metal/instrumentation.rb:75:in `process_action'
actionpack-8.0.2.1/lib/action_controller/metal/params_wrapper.rb:259:in `process_action'
activerecord-8.0.2.1/lib/active_record/railties/controller_runtime.rb:39:in `process_action'
actionpack-8.0.2.1/lib/abstract_controller/base.rb:163:in `process'
actionview-8.0.2.1/lib/action_view/rendering.rb:40:in `process'
rack-mini-profiler-4.0.1/lib/mini_profiler/profiling_methods.rb:116:in `block in profile_method'
actionpack-8.0.2.1/lib/action_controller/metal.rb:252:in `dispatch'
actionpack-8.0.2.1/lib/action_controller/metal.rb:335:in `dispatch'
actionpack-8.0.2.1/lib/action_dispatch/routing/route_set.rb:67:in `dispatch'
actionpack-8.0.2.1/lib/action_dispatch/routing/route_set.rb:50:in `serve'
actionpack-8.0.2.1/lib/action_dispatch/routing/mapper.rb:32:in `block in <class:Constraints>'
actionpack-8.0.2.1/lib/action_dispatch/routing/mapper.rb:62:in `serve'
actionpack-8.0.2.1/lib/action_dispatch/journey/router.rb:53:in `block in serve'
actionpack-8.0.2.1/lib/action_dispatch/journey/router.rb:133:in `block in find_routes'
actionpack-8.0.2.1/lib/action_dispatch/journey/router.rb:126:in `each'
actionpack-8.0.2.1/lib/action_dispatch/journey/router.rb:126:in `find_routes'
actionpack-8.0.2.1/lib/action_dispatch/journey/router.rb:34:in `serve'
actionpack-8.0.2.1/lib/action_dispatch/routing/route_set.rb:908:in `call'
/var/www/discourse/lib/middleware/omniauth_bypass_middleware.rb:35:in `call'
rack-2.2.17/lib/rack/tempfile_reaper.rb:15:in `call'
rack-2.2.17/lib/rack/conditional_get.rb:27:in `call'
rack-2.2.17/lib/rack/head.rb:12:in `call'
actionpack-8.0.2.1/lib/action_dispatch/http/permissions_policy.rb:38:in `call'
/var/www/discourse/lib/content_security_policy/middleware.rb:12:in `call'
/var/www/discourse/lib/middleware/anonymous_cache.rb:415:in `call'
/var/www/discourse/lib/middleware/csp_script_nonce_injector.rb:12:in `call'
/var/www/discourse/config/initializers/008-rack-cors.rb:14:in `call'
rack-2.2.17/lib/rack/session/abstract/id.rb:266:in `context'
rack-2.2.17/lib/rack/session/abstract/id.rb:260:in `call'
actionpack-8.0.2.1/lib/action_dispatch/middleware/cookies.rb:706:in `call'
actionpack-8.0.2.1/lib/action_dispatch/middleware/callbacks.rb:31:in `block in call'
activesupport-8.0.2.1/lib/active_support/callbacks.rb:100:in `run_callbacks'
actionpack-8.0.2.1/lib/action_dispatch/middleware/callbacks.rb:30:in `call'
actionpack-8.0.2.1/lib/action_dispatch/middleware/debug_exceptions.rb:31:in `call'
actionpack-8.0.2.1/lib/action_dispatch/middleware/show_exceptions.rb:32:in `call'
logster-2.20.1/lib/logster/middleware/reporter.rb:40:in `call'
/var/www/discourse/lib/middleware/default_headers.rb:13:in `call'
railties-8.0.2.1/lib/rails/rack/logger.rb:41:in `call_app'
railties-8.0.2.1/lib/rails/rack/logger.rb:29:in `call'
/var/www/discourse/config/initializers/100-quiet_logger.rb:20:in `call'
/var/www/discourse/config/initializers/100-silence_logger.rb:29:in `call'
actionpack-8.0.2.1/lib/action_dispatch/middleware/request_id.rb:34:in `call'
/var/www/discourse/lib/middleware/enforce_hostname.rb:23:in `call'
rack-2.2.17/lib/rack/method_override.rb:24:in `call'
actionpack-8.0.2.1/lib/action_dispatch/middleware/executor.rb:16:in `call'
rack-2.2.17/lib/rack/sendfile.rb:110:in `call'
rack-mini-profiler-4.0.1/lib/mini_profiler.rb:334:in `call'
/var/www/discourse/lib/middleware/processing_request.rb:12:in `call'
message_bus-4.4.1/lib/message_bus/rack/middleware.rb:60:in `call'
/var/www/discourse/lib/middleware/request_tracker.rb:410:in `call'
actionpack-8.0.2.1/lib/action_dispatch/middleware/remote_ip.rb:96:in `call'
railties-8.0.2.1/lib/rails/engine.rb:535:in `call'
railties-8.0.2.1/lib/rails/railtie.rb:226:in `public_send'
railties-8.0.2.1/lib/rails/railtie.rb:226:in `method_missing'
rack-2.2.17/lib/rack/urlmap.rb:74:in `block in call'
rack-2.2.17/lib/rack/urlmap.rb:58:in `each'
rack-2.2.17/lib/rack/urlmap.rb:58:in `call'
unicorn-6.1.0/lib/unicorn/http_server.rb:634:in `process_client'
unicorn-6.1.0/lib/unicorn/http_server.rb:739:in `worker_loop'
unicorn-6.1.0/lib/unicorn/http_server.rb:547:in `spawn_missing_workers'
unicorn-6.1.0/lib/unicorn/http_server.rb:143:in `start'
unicorn-6.1.0/bin/unicorn:128:in `<top (required)>'
/var/www/discourse/vendor/bundle/ruby/3.3.0/bin/unicorn:25:in `load'
/var/www/discourse/vendor/bundle/ruby/3.3.0/bin/unicorn:25:in `<main>'
Hi @Roman
I am facing a new issue.
Please find the logs in the above tailing comments and suggest the necessary changes if required, or what could be the reason for the issue.
When I unchecked the Enable response API (requires on certain OpenAI Model ) option, the test was successful
The following is the cURL response we received when we attempted the action, regardless of Discourse.
curl -X POST http://localhost:11434/v1/chat/completions -H "Content-Type: application/json" -d '{
"model": "deepseek-coder-v2:latest",
"messages": [
{
"role": "system",
"content": "You are a helpful assistant."
},
{
"role": "user",
"content": "What is the latest version of Conan as per 2025"
}
],
"temperature": 0.7,
"max_tokens": 200
}'
{"id":"chatcmpl-940","object":"chat.completion","created":1757057197,"model":"deepseek-coder-v2:latest","system_fingerprint":"fp_ollama","choices":[{"index":0,"message":{"role":"assistant","content":" As of my last update in early 2023, there isn't any specific information about \"Conan\" after 2025 since I don't have future prediction capabilities or real-time data. However, I can provide some general advice on how to find the latest version of Conan, which is a package manager for C/C++ dependency management:\n\n1. **Visit the Official Website:** The most reliable way to get information about the latest version of Conan is to visit the official website at https://conan.io/. There you can usually find the latest release notes and documentation related to the latest version.\n\n2. **Check GitHub Repository:** Conan's codebase is hosted on GitHub, so you can also check the repository (https://github.com/conan-io/conan) for releases or tags that correspond to different versions. The repository often includes release notes in the form of commits and pull requests.\n\n3"},"finish_reason":"length"}],"usage":{"prompt_tokens":30,"completion_tokens":200,"total_tokens":230}}