Postgres Memory Node Giving Error: "Got unexpected type: undefined"

Describe the problem/error/question

The postgres memory node connected to my ai agent is suddenly giving this error "Got unexpected type: undefined". The ai agent was working fine a week ago.

I'm not sure why this is happening...

What is the error message (if any)?

→ “Got unexpected type: undefined”

Please share your workflow

→ too big to paste here…

Share the output returned by the last node

error

Information on your n8n setup

  • n8n version: latest version (updated today)
  • Database (default: SQLite): default
  • n8n EXECUTIONS_PROCESS setting (default: own, main): default
  • Running n8n via (Docker, npm, n8n cloud, desktop app): self hosted
  • Operating system: MacOs

What appears in “Error details”?