n8n Debugging When something breaks, the cause is almost always: 1. Parameter misconfiguration (wrong value, wrong type, missing field). 2. Stale assumptions (different version, different behavior than you remember). 3. Paths misconfigured or misconnected (wrong output index, wrong merge input, missing wire, IF/Switch wired to the wrong branch). 4. Upstream data stripped (an intermediate node replaced with its own output, so downstream resolves to null even though "it should be there"). Fix: reference the stable upstream node by name ( ). 5. Item context lost (after Aggregate, Execute Once, o…