Chatbot error in inputChat

[Sofesqivo]

Describe the problem/error/question

I’m creating a chatbot to use on a website. It used to work correctly, answering questions, etc. But suddenly it stopped working and I get the following message:

Please share your workflow

Share the output returned by the last node

Information on your n8n setup

• n8n version:
• Database (default: SQLite):
• n8n EXECUTIONS_PROCESS setting (default: own, main):
• Running n8n via (Docker, npm, n8n cloud, desktop app):
• Operating system:

[houda_ben]

Hi @Sofesqivo

the workflow might be not published and the PG Vector credentials are empty !

try to fix in this order:

1. Open Workflow Settings and confirm Execution Logic is set to v1

2. Reconnect the Postgres credentials on the PGVector Store node

3. Hit Publish and test via the production chat URL, not “Execute workflow”

Let me know

[achamm]

Hey, can you share the actual error message text? i cant see the screenshots. Also what n8n version are you on and are you running it via Docker or npm? If you can paste your workflow JSON taht would help a lot too.

[Anshul_Namdev]

Hi @Sofesqivo Welcome! I have personally faced this error and then i have updated my n8n instance and it worked correctly so just upgrade your current n8n instance to the latest stable version.

[Sofesqivo]

Yes, of course.

No prompt specified

Expected to find the prompt in an input field called ‘chatInput’ (this is what the chat trigger node node outputs). To use something else, change the ‘Prompt’ parameter

Error details

Other info

Node type

@n8n/n8n-nodes-langchain.agent

Node version

3.1 (Latest)

n8n version

2.10.2 (Self Hosted)

Time

12/3/2026, 8:46:19

Stack trace

NodeOperationError: No prompt specified at getPromptInputByType (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/@n8n+n8n-nodes-langchain@file+packages+@n8n+nodes-langchain_3f8a51621cafcf583d9248e2e2767e62/node_modules/@n8n/n8n-nodes-langchain/utils/helpers.ts:38:10) at prepareItemContext (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/@n8n+n8n-nodes-langchain@file+packages+@n8n+nodes-langchain_3f8a51621cafcf583d9248e2e2767e62/node_modules/@n8n/n8n-nodes-langchain/nodes/agents/Agent/agents/ToolsAgent/V3/helpers/prepareItemContext.ts:47:36) at /usr/local/lib/node_modules/n8n/node_modules/.pnpm/@n8n+n8n-nodes-langchain@file+packages+@n8n+nodes-langchain_3f8a51621cafcf583d9248e2e2767e62/node_modules/@n8n/n8n-nodes-langchain/nodes/agents/Agent/agents/ToolsAgent/V3/helpers/executeBatch.ts:78:47 at Array.map (<anonymous>) at executeBatch (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/@n8n+n8n-nodes-langchain@file+packages+@n8n+nodes-langchain_3f8a51621cafcf583d9248e2e2767e62/node_modules/@n8n/n8n-nodes-langchain/nodes/agents/Agent/agents/ToolsAgent/V3/helpers/executeBatch.ts:73:30) at ExecuteContext.toolsAgentExecute (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/@n8n+n8n-nodes-langchain@file+packages+@n8n+nodes-langchain_3f8a51621cafcf583d9248e2e2767e62/node_modules/@n8n/n8n-nodes-langchain/nodes/agents/Agent/agents/ToolsAgent/V3/execute.ts:46:84) at ExecuteContext.execute (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/@n8n+n8n-nodes-langchain@file+packages+@n8n+nodes-langchain_3f8a51621cafcf583d9248e2e2767e62/node_modules/@n8n/n8n-nodes-langchain/nodes/agents/Agent/V3/AgentV3.node.ts:151:10) at WorkflowExecute.executeNode (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-core@file+packages+core_@[email protected]_@opentelemetry+exporter-trace-otlp_9f358c3eeaef0d2736f54ac9757ada43/node_modules/n8n-core/src/execution-engine/workflow-execute.ts:1043:8) at WorkflowExecute.runNode (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-core@file+packages+core_@[email protected]_@opentelemetry+exporter-trace-otlp_9f358c3eeaef0d2736f54ac9757ada43/node_modules/n8n-core/src/execution-engine/workflow-execute.ts:1222:11) at /usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-core@file+packages+core_@[email protected]_@opentelemetry+exporter-trace-otlp_9f358c3eeaef0d2736f54ac9757ada43/node_modules/n8n-core/src/execution-engine/workflow-execute.ts:1665:27 at /usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-core@file+packages+core_@[email protected]_@opentelemetry+exporter-trace-otlp_9f358c3eeaef0d2736f54ac9757ada43/node_modules/n8n-core/src/execution-engine/workflow-execute.ts:2308:11

[Sofesqivo]

I supposedly have it updated, but what I see is that what I send through the chat never reaches the AI ​​agent or arrives as null or empty.

[Sofesqivo]

Thanks to checking the PostgreSQL settings as you suggested, I noticed an error in the n8n container; it was due to a missing section when creating it. Thank you very much!