我将 AI 助手“解释”功能的角色设置为自定义角色（使用 GPT-4.1-mini），然后点击解释会导致无限期加载。我将其切换回默认值后，它又开始工作了。
错误日志
消息（报告了 2 个副本）
作业异常：nil 无法隐式转换为 String
回溯
/var/www/discourse/plugins/discourse-ai/lib/ai_helper/assistant.rb:143:in block in generate_prompt' /var/www/discourse/plugins/discourse-ai/lib/personas/bot.rb:159:in block in reply’
/var/www/discourse/plugins/discourse-ai/lib/completions/endpoints/base.rb:187:in block (3 levels) in perform_completion!' /var/www/discourse/plugins/discourse-ai/lib/completions/endpoints/base.rb:230:in block (5 levels) in perform_completion!’
/var/www/discourse/plugins/discourse-ai/lib/completions/endpoints/base.rb:230:in each' /var/www/discourse/plugins/discourse-ai/lib/completions/endpoints/base.rb:230:in block (4 levels) in perform_completion!’
/var/www/discourse/plugins/discourse-ai/lib/completions/endpoints/base.rb:221:in each' /var/www/discourse/plugins/discourse-ai/lib/completions/endpoints/base.rb:221:in block (3 levels) in perform_completion!’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-protocol-0.2.2/lib/net/protocol.rb:535:in call_block' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-protocol-0.2.2/lib/net/protocol.rb:526:in <<’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-protocol-0.2.2/lib/net/protocol.rb:168:in read' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http/response.rb:631:in read_chunked’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http/response.rb:595:in block in read_body_0' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http/response.rb:588:in inflater’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http/response.rb:593:in read_body_0' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http/response.rb:363:in read_body’
/var/www/discourse/plugins/discourse-ai/lib/completions/endpoints/base.rb:216:in block (2 levels) in perform_completion!' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http.rb:2433:in block in transport_request’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http/response.rb:320:in reading_body' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http.rb:2430:in transport_request’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http.rb:2384:in request' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rack-mini-profiler-3.3.1/lib/patches/net_patches.rb:19:in block in request_with_mini_profiler’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rack-mini-profiler-3.3.1/lib/mini_profiler/profiling_methods.rb:50:in step' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rack-mini-profiler-3.3.1/lib/patches/net_patches.rb:18:in request_with_mini_profiler’
/var/www/discourse/plugins/discourse-ai/lib/completions/endpoints/base.rb:158:in block in perform_completion!' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http.rb:1632:in start’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/net-http-0.6.0/lib/net/http.rb:1070:在 start' /var/www/discourse/plugins/discourse-ai/lib/completions/endpoints/base.rb:129:在 perform_completion!’
/var/www/discourse/plugins/discourse-ai/lib/completions/endpoints/open_ai.rb:53:在 perform_completion!' /var/www/discourse/plugins/discourse-ai/lib/completions/llm.rb:374:在 generate’
/var/www/discourse/plugins/discourse-ai/lib/personas/bot.rb:90:在 reply' /var/www/discourse/plugins/discourse-ai/lib/ai_helper/assistant.rb:148:在 generate_prompt’
/var/www/discourse/plugins/discourse-ai/lib/ai_helper/assistant.rb:197:在 stream_prompt' /var/www/discourse/plugins/discourse-ai/app/jobs/regular/stream_post_helper.rb:30:在 execute’
/var/www/discourse/app/jobs/base.rb:316:在 block (2 levels) in perform' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-6.1.0/lib/rails_multisite/connection_management/null_instance.rb:49:在 with_connection’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-6.1.0/lib/rails_multisite/connection_management.rb:21:在 with_connection' /var/www/discourse/app/jobs/base.rb:303:在 block in perform’
/var/www/discourse/app/jobs/base.rb:299:在 each' /var/www/discourse/app/jobs/base.rb:299:在 perform’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:220:在 execute_job' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:185:在 block (4 levels) in process’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:180:在 traverse' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:183:在 block in traverse’
/var/www/discourse/lib/sidekiq/discourse_event.rb:6:在 call' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:182:在 traverse’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:183:在 block in traverse' /var/www/discourse/lib/sidekiq/pausable.rb:131:在 call’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:182:在 traverse' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:183:在 block in traverse’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/job/interrupt_handler.rb:9:在 call' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:182:在 traverse’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:183:在 block in traverse' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/metrics/tracking.rb:26:在 track’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/metrics/tracking.rb:134:在 call' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:182:在 traverse’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:173:在 invoke' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:184:在 block (3 levels) in process’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:145:在 block (6 levels) in dispatch' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/job_retry.rb:118:在 local’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:144:在 block (5 levels) in dispatch' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/config.rb:39:在 block in"
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:139:in block (4 levels) in dispatch' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:281:in stats’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:134:in block (3 levels) in dispatch' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/job_logger.rb:15:in call’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:133:in block (2 levels) in dispatch' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/job_retry.rb:85:in global’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:132:in block in dispatch' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/job_logger.rb:40:in prepare’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:131:in dispatch' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:183:in block (2 levels) in process’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:182:in handle_interrupt' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:182:in block in process’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:181:in handle_interrupt' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:181:in process’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:86:in process_one' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:76:in run’
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/component.rb:10:in watchdog' /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/component.rb:19:in block in safe_thread’